This is a texinfo version of the man page for the Z Shell, by Paul Falstad.  It was converted from the original zsh.1 file distributed with zsh v2.4.291.  The conversion was done by Jonathan Hardwick, jch@cs.cmu.edu, who would love to hear of any errors he introduced or texinfo rules he broke.  The text remains the work of Paul Falstad.

Shell Grammar
*************

Simple Commands
===============

A simple command is a sequence of optional parameter assignments followed by blank-separated words, with optional redirections interspersed.  The first word is the command to be executed, and the remaining words, if any, are arguments to the command.  If a command name is given, the parameter assignments modify the environment of the command when it is executed.  The value of a simple command is its exit status, or 128 plus the signal number if terminated by a signal.

If a simple command is preceded by the word exec, it is executed in the parent shell without forking.  If preceded by command, the command word is taken to be the name of an external command, rather than a shell function or builtin.  If preceded by noglob, filename generation is not performed on any of the words.  If preceded by a -, the command is executed with a - prepended to its argv[0] string.  If preceded by nocorrect, spelling correction is not done on any of the words.

A pipeline is a sequence of one or more commands separated by | or |&.  |& is shorthand for 2>&1 |.  The standard output of each command is connected to the standard input of the next command in the pipeline.

The value of a pipeline is the value of the last command.  If a pipeline is preceded by a !, the value of that pipeline is the logical NOT of the value of the last command.

If a pipeline is preceded by coproc, it is executed as a coprocess; a two-way pipe is established between it and the parent shell.  The shell can read from or write to the coprocess by means of the >&p and <&p redirection operators.

A sublist is a sequence of one or more pipelines separated by && or ||.  If two pipelines are separated by &&, the second pipeline is executed only if the first is successful (returns a zero value).  If two pipelines are separated by ||, the second is executed only if the first is unsuccessful (returns a nonzero value).

A list is a sequence of one or more sublists separated by, and optionally terminated by, ;, &, or a newline.  Normally the shell waits for each list to finish before executing the next one. If a list is terminated by a &, the shell executes it in the background, and does not wait for it to finish.

Complex Commands
================

A complex command is one of the following:

for NAME [ in WORD ... ]
do LIST
done
     Expand the list of WORDs, and set the parameter NAME to each of them in turn, executing LIST each time.  If the in WORD is omitted, use the positional parameters instead of the WORDs.

for NAME [ in WORD ... ] ; SUBLIST
     This is a shorthand for for.  Though it may cause confusion, it is included for convenience; its use in scripts is discouraged, unless SUBLIST is a command of the form { LIST }.

foreach NAME ( WORD ... )
LIST
end
     Another form of for.

for NAME in WORD ...
{
LIST
}
     Another form of for.

for NAME ( WORD ... ) {
LIST
}
     Another form of for.

for NAME ( WORD ... ) SUBLIST
     Another form of for.

select NAME [ in WORD ... ]
do LIST
done
     Print the set of WORDs, each preceded by a number.  If the in WORD is omitted, use the positional parameters.  The PROMPT3 prompt is printed and a line is read from standard input. If this line consists of the number of one of the listed WORDs, then the parameter NAME is set to the WORD corresponding to this number.  If this line is empty, the selection list is printed again.  Otherwise, the value of the parameter NAME is set to null. The contents of the line read from standard input is saved in the parameter REPLY.  LIST is executed for each selection until a break or end-of-file is encountered.

select NAME [ in WORD ] ; SUBLIST
     A short form of select.

case WORD in [ PATTERN ) LIST ;; ] ... esac
     Execute the LIST associated with the first PATTERN that matches WORD, if any.  The form of the patterns is the same as that used for filename generation.  See Filename Generation.

case WORD { [ PATTERN ) LIST ;; ] ... }
     Another form of case.

if LIST
then LIST
[ elif LIST ; then LIST ] ...
[ else LIST ]
fi
     The if LIST is executed, and, if it returns a zero exit status, the then LIST is executed.  Otherwise, the elif LIST is executed and, if its value is zero, the then LIST is executed.  If each elif LIST returns nonzero, the else LIST is executed.

if ( LIST ) SUBLIST
     A short form of if.

if ( LIST ) {
LIST
} elif ( LIST ) {
LIST
} ... else {
LIST
}
     An alternate form of if.  The parentheses surrounding LIST can be omitted if the only command in the list is a conditional expression of the form [[ EXP ]].  See Conditional Expressions.

while LIST
do LIST
done
     Execute the do LIST as long as the while LIST returns a zero exit status.

while ( LIST ) {
LIST
}
     An alternate form of while.

until LIST
do LIST
done
     Execute the do LIST as long as the until LIST returns a nonzero exit status.

repeat WORD
do LIST
done
     WORD is expanded and treated as an arithmetic expression, which must evaluate to a number N.  LIST is then executed N times.

repeat WORD SUBLIST
     This is a short form of repeat.

( LIST )
     Execute LIST in a subshell.

{ LIST }
     Execute LIST.

function WORD [ () ] ... { LIST }
WORD ... () { LIST }
WORD ... () SUBLIST
     Define a function which is referenced by any one of WORD. Normally, only one WORD is provided; multiple WORDs are usually only useful for setting traps.  The body of the function is the LIST between the { and }. See Functions.

time [ PIPELINE ]
     The PIPELINE is executed, and timing statistics are reported on the standard error in the form specified by the TIMEFMT parameter.  If PIPELINE is omitted, print statistics about the shell process and its children.

[[ EXP ]]
     Evaluates the conditional expression EXP and return a zero exit status if it is true.  See Conditional Expressions, for a description of EXP.

Reserved Words
==============

The following words are recognized as reserved words when used as the first word of a command unless quoted or removed using the unalias builtin:

do done esac then elif else fi for case if while function repeat time until exec command select coproc noglob - nocorrect foreach end

Comments
========

In noninteractive shells, or in interactive shells with the INTERACTIVE_COMMENTS option set, a word beginning with the third character of the HISTCHARS parameter (# by default) causes that word and all the following characters up to a newline to be ignored.

Aliasing
========

Every token in the shell input is checked to see if there is an alias defined for it.  If so, it is replaced by the text of the alias if it is in command position (if it could be the first word of a simple command), or if the alias is global.  If the text ends with a space, the next word in the shell input is treated as though it were in command position for purposes of alias expansion.  An alias is defined using the alias builtin; global aliases may be defined using the -g option to that builtin.

Alias substitution is done on the shell input before any other substitution except history substitution.  Therefore, if an alias is defined for the word foo, alias substitution may be avoided by quoting part of the word, e.g. \foo.  But there is nothing to prevent an alias being defined for \foo as well.

Quoting
=======

A character may be quoted (that is, made to stand for itself) by preceding it with a \.  \ followed by a newline is ignored.  All characters enclosed between a pair of single quotes are quoted, except the first character of HISTCHARS (! by default).  A single quote cannot appear within single quotes.  Inside double quotes (""), parameter and command substitution occurs, and \ quotes the characters \, `, ", and $.

Expansion
*********

Expansion is performed on the command line after it has been parsed. The types of expansions performed are filename expansion, process substitution, parameter expansion, command substitution, arithmetic expansion, brace expansion, and filename generation.

Filename Expansion
==================

Each word is checked to see if it begins with an unquoted ~.  If it does, then the word up to a / is checked to see if it matches the name of a named directory.  If so, then the ~ and the matched portion are replaced with the value of the named directory.  A ~ by itself or followed by a / is replaced by the value of the HOME parameter.  A ~ followed by a + or a - is replaced by the value of PWD or OLDPWD, respectively.

Named directories are typically login directories for users on the system.  They may also be defined if the text after the ~ is the name of a string shell parameter whose value begins with a /.  In certain circumstances (in prompts, for instance), when the shell prints a path, the path is checked to see if it has a named directory as its prefix.  If so, then the prefix portion is replaced with a ~ followed by the name of the directory.  The longest match is preferred.

If a word begins with an unquoted = and the NO_EQUALS option is not set, the remainder of the word is taken as the name of a command or alias.  If a command exists by that name, the word is replaced by the full pathname of the command.  If an alias exists by that name, the word is replaced with the text of the alias.  Otherwise the word is checked up to a / to see if it is a number or a -.  If so, the matched portion is replaced with the N'th directory in the directory stack, where N is the number matched, or the last directory in the directory stack if a - is matched.

Filename expansion is performed on the right hand side of a parameter assignment, including those appearing after commands of the typeset family.  In this case, the right hand side will be treated as a colon-separated list in the manner of PATH, so that a ~ or = following a : is eligible for expansion. All such behaviour can be disabled by quoting the ~, =, or the whole expression (but not simply the colon); the NO_EQUALS option is also respected.

If the option MAGIC_EQUAL_SUBST is set, any unquoted shell argument of the form IDENTIFIER=EXPRESSION becomes eligible for file expansion as described in the previous paragraph. Quoting the first = also inhibits this.

Process Substitution
====================

Each command argument of the form <(LIST), >(LIST) or =(LIST) is subject to process substitution.  In the case of the < and > forms, the shell will run process LIST asynchronously, connected to a named pipe (FIFO).  The name of this pipe will become the argument to the command. If the form with > is selected then writing to this file will provide input for LIST.  If < is used, then the file passed as an argument will be a named pipe connected to the output of the LIST process.  For example,

paste <(cut -f1 FILE1) <(cut -f3 FILE2) | tee >(PROCESS1) >(PROCESS2) >/dev/null

cuts fields 1 and 3 from the files FILE1 and FILE2 respectively, pastes the results together, and sends it to the processes PROCESS1 and PROCESS2.  Note that the file, which is passed as an argument to the command, is a system pipe so programs that expect to lseek(2) on the file will not work.  Also note that the previous example can be more compactly and efficiently written as:

paste <(cut -f1 FILE1) <(cut -f3 FILE2) >>(PROCESS1) >>(PROCESS2)

The shell uses pipes instead of FIFOs to implement the latter two process substitutions in the above example.

If = is used, then the file passed as an argument will be the name of a temporary file containing the output of the LIST process. This may be used instead of the < form for a program that expects to lseek(2) on the input file.

Parameter Expansion
===================

The character $ is used to introduce parameter expansions. See Parameters, for a description of parameters.

${NAME}
     The value, if any, of the parameter NAME is substituted.  The braces are required if NAME is followed by a letter, digit, or underscore that is not to be interpreted as part of its name.  If NAME is an array parameter, then the values of each element of NAME is substituted, one element per word.  Otherwise, the expansion results in one word only; no word splitting is done on the result.

${+NAME}
     If NAME is the name of a set parameter, then substitute 1, otherwise substitute 0.

${NAME:-WORD}
     If NAME is set and is non-null then substitute its value; otherwise substitute WORD.

${NAME:=WORD}
     If NAME is unset or is null then set it to WORD; the value of the parameter is then substituted.

${NAME:?WORD}
     If NAME is set and is non-null, then substitute its value; otherwise, print WORD and exit from the shell.  If WORD is omitted, then a standard message is printed.

${NAME:+WORD}
     If NAME is set and is non-null then substitute WORD; otherwise substitute nothing.

${NAME#PATTERN}
${NAME##PATTERN}
     If the PATTERN matches the beginning of the value of NAME, then substitute the value of NAME with the matched portion deleted; otherwise, just substitute the value of NAME.  In the first form, the smallest matching pattern is preferred; in the second form, the largest matching pattern is preferred.

${NAME%PATTERN}
${NAME%%PATTERN}
     If the PATTERN matches the end of the value of NAME, then substitute the value of NAME with the matched portion deleted; otherwise, just substitute the value of NAME.  In the first form, the smallest matching pattern is preferred; in the second form, the largest matching pattern is preferred.

${#SPEC}
     If SPEC is one of the above substitutions, substitute the length in characters of the result instead of the result itself.  If SPEC is an array expression, substitute the number of elements of the result.

${^SPEC}
     Toggle the value of the RC_EXPAND_PARAM option for the evaluation of SPEC.  When this option is set, array expansions of the form foo${xx}bar, where the parameter xx is set to (a b c), are substituted with fooabar foobbar foocbar instead of the default fooa b cbar.

${=SPEC}
     Toggle the value of the SH_WORD_SPLIT option for the evaluation of SPEC.  When this option is set, parameter values are split into separate words using IFS as a delimiter before substitution. This is done by default in most other shells.

${~SPEC}
     Toggle the value of the CSH_JUNKIE_TILDE option for the evaluation of SPEC.  When this option is set, any = and ~ resulting from the substitution become eligible for filename expansion.

If the colon is omitted from one of the above expressions containing a colon, then the shell only checks whether NAME is set or not, not whether it is null.

If the opening brace is directly followed by an opening parenthesis the string up to the matching closing parenthesis will be taken as a list of flags, where the following flags are supported:

o
     The resulting words will be sorted in ascending order.

O
     The resulting words will be sorted in descending order.

i
     If given together with o or O, makes the sort case-insensitive.

L
     Converts the result to all lowercase.

U
     Converts the result to all uppercase.

C
     Capitalizes the result.

c
     If using ${#NAME} to count array elements, this flag makes it count characters instead (as if the elements were concatenated with spaces between them).

w
     Like c, but works for strings and arrays and makes it count words (words are strings separated by white space or by the string given with the s flag).

l:EXPR::STRING1::STRING2:
     Specifies a left padding for the resulting words.  Each word will be right-justified in a field EXPR characters wide (truncated if needed), and any space to the left of the word will be filled with STRING1 (concatenated as often as needed), or spaces if STRING1 is not given.  If STRING2 is also given, this string will be placed exactly once directly to the left of the resulting word. Any character can be used instead of the colon to enclose the arguments (or the pairs (...), {...}, [...], or <...> can be used).

r:EXPR::STRING1::STRING2:
     Like l, but for right padding.

j:STRING:
     If SH_WORD_SPLIT is set, the resulting words will be concatenated with STRING and then split again at the string given with the s flag.  If neither j nor s are given this will be done with spaces.  If only j is given, the string to separate words defaults to the string given with the s flag.

s:STRING:
     See above.

S
     All flags from here on are used with the ${...#...} and ${...%...} forms.  The S flag applies the search to substrings as well as to the beginnings and ends of strings.

I:EXPR:
     Assuming EXPR evaluates to N, returns the N'th match.

M
     Include the matched portion in the result.

R
     Include the unmatched portion in the result (the Rest).

B
     Include the index of the beginning of the match in the result.

E
     Include the index of the end of the match in the result.

N
     Include the length of the match in the result.

Command Substitution
====================

A command enclosed in parentheses preceded by a dollar sign, like so: $(...) or quoted with grave accents: `...` is replaced with its standard output.  If the substitution is not enclosed in double quotes, the output is broken into words using the IFS parameter. The substitution $(cat foo) may be replaced by the equivalent but faster $(<foo).

Arithmetic Expansion
====================

A string of the form $[EXP] is substituted with the value of the arithmetic expression EXP.  EXP is treated as if it were within single quotes.  See Arithmetic Evaluation.

Brace Expansion
===============

A string of the form foo{xx,yy,zz}bar is expanded to the individual words fooxxbar,
fooyybar, and foozzbar. Left-to-right order is preserved.  This construct may be nested. Malformed brace expansion expressions, including expressions without a comma, are left unchanged by the shell.

An expression of the form {x-y}, where x and y are single characters, is expanded to every character between x and y, inclusive.

Filename Generation
===================

If a word contains an unquoted instance of one of the characters *, |, <, [, or ?, it is regarded as a pattern for filename generation, unless the NO_GLOB option is set.  If the EXTENDED_GLOB option is set, the ^ and # characters also denote a pattern; otherwise they are not treated specially by the shell.  The word is replaced with a list of sorted filenames that match the pattern.  If no matching pattern is found, the shell gives an error message, unless the NULL_GLOB option is set, in which case the word is deleted; or unless the NO_NOMATCH option is set, in which case the word is left unchanged.  In filename generation, the character / must be matched explicitly; also, a . must be matched explicitly at the beginning of a pattern or after a /, unless the GLOB_DOTS option is set.  No filename generation pattern matches the files . or ...  In other instances of pattern matching, the / and . are not treated specially.

*
     Matches any string, including the null string.

?
     Matches any character.

[...]
     Matches any of the enclosed characters.

[^...]
     Matches any character except the enclosed characters.

<x-y>
     Matches any number in the range x to y, inclusive.  If x is omitted, the number must be less than or equal to y. If y is omitted, the number must be greater than or equal to x.  A pattern of the form <-> or simply <> matches any number.

^x
     Matches anything except the pattern x.

x|y
     Matches either x or y.

x#
     Matches zero or more occurrences of the pattern x.

x##
     Matches one or more occurrences of the pattern x.

Parentheses may be used for grouping.  Note that the | character must be within parentheses, so that the lexical analyzer does not think it is a pipe character.  Also note that / has a higher precedence than ^; that is:

ls ^foo/bar

will search directories in . except ./foo for a file named bar.

A pathname component of the form (FOO/)# matches a path consisting of zero or more directories matching the pattern FOO. As a shorthand, **/ is equivalent to (*/)#.  Thus:

ls (*/)#bar

or

ls **/bar

does a recursive directory search for files named bar.

If used for filename generation, a pattern may contain an exclusion specifier.  Such patterns are of the form PAT1~PAT2. This pattern will generate all files matching PAT1, but which do not match PAT2.  For example, *.c~lex.c will match all files ending in .c, except the file lex.c.

Patterns used for filename generation may also end in a list of qualifiers enclosed in parentheses.  The qualifiers specify which filenames that otherwise match the given pattern will be inserted in the argument list.  A qualifier may be any one of the following:

/
     Directories

.
     Plain files

@
     Symbolic links

=
     Sockets

p
     Named pipes (FIFOs)

*
     Executable plain files (0100)

%
     Device files (character or block special)

%b
     Block special files

%c
     Character special files

r
     Readable files (0400)

w
     Writable files (0200)

x
     Executable files (0100)

R
     World-readable files (0004)

W
     World-writable files (0002)

X
     World-executable files (0001)

s
     Setuid files (04000)

S
     Setgid files (02000)

dDEV
     Files on the device DEV

l[+-]CT
     Files having a link count less than (-), more than (+), or equal to CT.

U
     Files owned by the effective user id.

G
     Files owned by the effective group id.

uID
     Files owned by user ID if ID is a number.  If not, the character after the u will be used as a separator and the string between it and the next matching separator ((, [, {, and < match ), ], }, and > respectively; any other character matches itself) will be taken as a user name and translated into the corresponding user id (e.g. u:foo: or u[foo] for user foo).

gID
     Like uID but with group ids or names.

a[+-]N
     Files accessed within last N days (-), more than N days ago (+), or exactly N days ago.

m[+-]N
     Files modified within last N days (-), more than N days ago (+), or exactly N days ago.

c[+-]N
     Files whose inode changed within last N days (-), more than N days ago (+), or exactly N days ago.  If any of the flags a, m, or c is directly followed by a M, w, h, or m (e.g. mh+5) the check is performed in units of months (of 30 days), weeks, hours, or minutes respectively.

L[+-]N
     Files less than N bytes (-), more than N bytes (+), or exactly N bytes in length.

^
     Negates all qualifiers following it.

-
     Toggles between making the qualifiers work on symbolic links (the default), and the files they point to.

M
     Sets the MARK_DIRS option for the current pattern.

T
     Appends a trailing qualifier mark to the file names, analogous to the LIST_TYPES, for the current pattern (overrides M).

N
     Sets the NULL_GLOB option for the current pattern.

D
     Sets the GLOB_DOTS option for the current pattern.

More than one of these lists can be combined, separated by commas; the whole list matches if at least one of the sublists matches (they are or'ed, the qualifiers in the sublists are and'ed).  A / at the end of a pattern is equivalent to (/).

If a : appears in a qualifier list, the remainder of the expression in parentheses is interpreted as a modifier (see Modifiers).  Note that each modifier must be introduced by a separate :.  Note also that the result after modification does not have to be an existing file.  The name of any existing file can be followed by a modifier of the form (:...) even if no filename generation is performed.

Thus:

ls *(-/)

lists all directories and symbolic links that point to directories, and

ls *(%W)

lists all world-writable device files in the current directory, and

ls *(W,X)

lists all files in the current directory that are world-writable or world-executable, and

echo /tmp/foo*(u0^@:t)

outputs the basename of all root-owned files beginning with the string foo in /tmp, ignoring symlinks, and

ls *.*~(lex|parse).[ch](^D^l1)

lists all files having a link count of one whose names contain a dot (but not those starting with a dot, since GLOB_DOTS is explicitly switched off) except for lex.c, lex.h, parse.c, and parse.h.

Redirection
***********

Before a command is executed, its input and output may be redirected. The following may appear anywhere in a simple command or may precede or follow a complex command.  Substitution occurs before WORD is used except as noted below.  If the result of substitution on WORD produces more than one filename, redirection occurs for each separate filename in turn.

<WORD
     Open file WORD as standard input.

>WORD
     Open file WORD as standard output.  If the file does not exist then it is created.  If the file exists, and the NO_CLOBBER option is set, this causes an error; otherwise, it is truncated to zero length.

>!WORD
     Same as >, except that the file is truncated to zero length if it exists, even if NO_CLOBBER is set.

>>WORD
     Open file WORD as standard output.  If the file exists then output is appended to it.  If the file does not exist, and the NO_CLOBBER option is set, this causes an error; otherwise, the file is created.

>>!WORD
     Same as >>, except that the file is created if it does not exist, even if NO_CLOBBER is set.

<<[-]WORD
     The shell input is read up to a line that is the same as WORD, or to an end-of-file.  No parameter substitution, command substitution or filename generation is performed on WORD.  The resulting document, called a here-document, becomes the standard input.  If any character of WORD is quoted with single or double quotes or a \, no interpretation is placed upon the characters of the document.  Otherwise, parameter and command substitution occurs, \ followed by a newline is removed, and \ must be used to quote the characters \, $, `, and the first character of WORD.  If <<- is used, then all leading tabs are stripped from WORD and from the document.

<<<WORD
     Open a file containing WORD, after expansion, as standard input.

<&DIGIT
     The standard input is duplicated from file descriptor DIGIT (see dup(2)).  Similarly for standard output using >&DIGIT.

>&WORD
     Same as >WORD 2>&1.

>>&WORD
     Same as >>WORD 2>&1.

<&-
     Close the standard input.

>&-
     Close the standard output.

<&p
     The input from the coprocess is moved to the standard input.

>&p
     The output to the coprocess is moved to the standard output.

If one of the above is preceded by a digit, then the file descriptor referred to is that specified by the digit (instead of the default 0 or 1).  The order in which redirections are specified is significant.  The shell evaluates each redirection in terms of the (FILE DESCRIPTOR, FILE) association at the time of evaluation.  For example:

... 1>FNAME 2>&1

first associates file descriptor 1 with file FNAME.  It then associates file descriptor 2 with the file associated with file descriptor 1 (that is, FNAME).  If the order of redirections were reversed, file descriptor 2 would be associated with the terminal (assuming file descriptor 1 had been) and then file descriptor 1 would be associated with file FNAME.

If the user tries to open a file descriptor for writing more than once, the shell opens the file descriptor as a pipe to a process that copies its input to all the specified outputs, similar to tee(1).  Thus:

date >foo >bar

writes the date to two files, named foo and bar.  Note that a pipe is an implicit indirection; thus

date >foo | cat

writes the date to the file foo, and also pipes it to cat.

If the user tries to open a file descriptor for reading more than once, the shell opens the file descriptor as a pipe to a process that copies all the specified inputs to its output in the order specified, similar to cat(1).  Thus

sort <foo <fubar

or even

sort <f{oo,ubar}

is equivalent to cat foo fubar | sort.  Note that a pipe is an implicit indirection; thus

cat bar | sort <foo

is equivalent to cat bar foo | sort (note the order of the inputs).

If a simple command consists of one or more redirection operators and zero or more parameter assignments, but no command name, the command cat is assumed.  Thus

< file

prints the contents of file.

If a command is followed by & and job control is not active, then the default standard input for the command is the empty file /dev/null.  Otherwise, the environment for the execution of a command contains the file descriptors of the invoking shell as modified by input/output specifications.

Command Execution
*****************

If a command name contains no slashes, the shell attempts to locate it. If there exists a shell function by that name, the function is invoked as described below (see Functions).  If there exists a shell builtin by that name, the builtin is invoked.

Otherwise, the shell searches each element of path for a directory containing an executable file by that name.  If the search is unsuccessful, the shell prints an error message and returns a nonzero exit status.

If execution fails because the file is not in executable format, and the file is not a directory, it is assumed to be a shell script. /bin/sh is spawned to execute it.  If the program is a file beginning with #!, the remainder of the first line specifies an interpreter for the program.  The shell will execute the specified interpreter on operating systems that do not handle this executable format in the kernel.

Functions
*********

The function reserved word is used to define shell functions. Shell functions are read in and stored internally.  Alias names are resolved when the function is read.  Functions are executed like commands with the arguments passed as positional parameters.

Functions execute in the same process as the caller and share all files and the present working directory with the caller.  A trap on EXIT set inside a function is executed after the function completes in the environment of the caller.

The return builtin is used to return from function calls.

Function identifiers can be listed with the functions builtin. Functions can be undefined with the unfunction builtin.

The following functions, if defined, have special meaning to the shell:

chpwd
     Executed whenever the current working directory is changed.

precmd
     Executed before each prompt.

periodic
     If the parameter PERIOD is set, this function is executed every PERIOD seconds, just before a prompt.

TRAPXXX
     If defined and non-null, this function will be executed whenever the shell catches a signal SIGXXX, where XXX is a signal name as specified for the kill builtin (see Shell Builtin Commands).  In addition, TRAPZERR is executed whenever a command has a non-zero exit status, TRAPDEBUG is executed after each command, and TRAPEXIT is executed when the shell exits, or when the current function exits if defined inside a function.  If a function of this form is defined and null, the shell and processes spawned by it will ignore SIGXXX.

Jobs & Signals
**************

If the MONITOR option is set, an interactive shell associates a job with each pipeline.  It keeps a table of current jobs, printed by the jobs command, and assigns them small integer numbers.  When a job is started asynchronously with &, the shell prints a line which looks like:

[1] 1234

indicating that the job which was started asynchronously was job number 1 and had one (top-level) process, whose process id was 1234.

If you are running a job and wish to do something else you may hit the key ^Z (control-Z) which sends a TSTP signal to the current job.  The shell will then normally indicate that the job has been suspended, and print another prompt.  You can then manipulate the state of this job, putting it into the background with the bg command, or run some other commands and then eventually bring the job back into the foreground with the foreground command fg.  A ^Z takes effect immediately and is like an interrupt in that pending output and unread input are discarded when it is typed.

A job being run in the background will suspend if it tries to read from the terminal.  Background jobs are normally allowed to produce output, but this can be disabled by giving the command stty tostop.  If you set this tty option, then background jobs will suspend when they try to produce output, just as they do when they try to read input.

There are several ways to refer to jobs in the shell.  A job can be referred to by the process id of any process of the job or by one of the following:

%NUMBER
     The job with the given number.

%STRING
     Any job whose command line begins with STRING.

%?STRING
     Any job whose command line contains STRING.

%%
     Current job.

%+
     Equivalent to %%.

%-
     Previous job.

The shell learns immediately whenever a process changes state.  It normally informs you whenever a job becomes blocked so that no further progress is possible.  If notify is not set, it waits until just before it prints a prompt before it informs you.

When the monitor mode is on, each background job that completes triggers any trap set for CHLD.

When you try to leave the shell while jobs are running or suspended, you will be warned that You have suspended (running) jobs.  You may use the jobs command to see what they are.  If you do this or immediately try to exit again, the shell will not warn you a second time; the suspended jobs will be terminated, and the running jobs will be sent a SIGHUP signal.  To avoid having the shell terminate the running jobs, either use the nohup(1) command or the disown builtin (see Shell Builtin Commands).

The INT and QUIT signals for an invoked command are ignored if the command is followed by & and the job monitor option is not active.  Otherwise, signals have the values inherited by the shell from its parent (but see Functions, for the TRAPXXX special functions).

History
*******

History substitution allows you to use words from previous command lines in the command line you are typing.  This simplifies spelling corrections and the repetition of complicated commands or arguments. Command lines are saved in the history list, the size of which is controlled by the HISTSIZE variable.  The most recent command is retained in any case.  A history substitution begins with a ! and may occur anywhere on the command line; history substitutions do not nest.  The ! can be escaped with \ to suppress its special meaning.  Single or double quotes will not work for this.

Input lines containing history substitutions are echoed on the terminal after being expanded, but before any other substitutions take place or the command gets executed.

Event Designators
=================

An event designator is a reference to a command-line entry in the history list.

!
     Start a history substitution, except when followed by a blank, newline, =, or (.

!!
     Refer to the previous command.  By itself, this substitution repeats the previous command.

!n
     Refer to command line N.

!-n
     Refer to the current command line minus N.

!str
     Refer to the most recent command starting with STR.

!?STR[?]
     Refer to the most recent command containing STR.

!#
     Refer to the current command line typed in so far.

!{...}
     Insulate a history reference from adjacent characters (if necessary).

Word Designators
================

A word designator indicates which word or words of a given command line will be included in a history reference.  A : separates the event specification from the word designator.  It can be omitted if the word designator begins with a ,, $, *, - or %.  Word designators include:

0
     The first input word (command).

N
     The N'th argument.

^
     The first argument, that is, 1.

$
     The last argument.

%
     The word matched by (the most recent) ?STR search.

X-Y
     A range of words;  -Y abbreviates 0-Y.

*
     All the arguments, or a null value if there is just one word in the event.

X*
     Abbreviates X-$.

X
     Like X* but omitting word $.

Note that a % word designator will only work when used as !%, !:%, or !?STR?:%, and only when used after a ?! substitution.  Anything else will result in an error, although the error may not be the most obvious one.

Modifiers
=========

After the optional word designator, you can add a sequence of one or more of the following modifiers, each preceded by a :.  These modifiers also work on the result of filename and parameter expansion.

h
     Remove a trailing pathname component, leaving the head.

r
     Remove a trailing suffix of the form .XXX, leaving the basename.

e
     Remove all but the suffix.

t
     Remove all leading pathname components, leaving the tail.

&
     Repeat the previous substitution.

g
     Apply the change to the first occurrence of a match in each word, by prefixing the above (for example, g&).

p
     Print the new command but do not execute it.

q
     Quote the substituted words, escaping further substitutions.

x
     Like q, but break into words at each blank.

l
     Convert the words to all lowercase.

u
     Convert the words to all uppercase.

f
     Repeats the immediately-following (without a colon) modifier until the resulting word doesn't change any more.  This modifier and the following four only work with parameter and filename expansion.

F:EXPR:
     Like f, but repeats only N times if the expression EXPR evaluates to N.  Any character can be used instead of the :, with the exception that if (, [, or { is used as the opening delimiter, the closing delimiter must be ), ], or } respectively.

w
     Makes the immediately-following modifier work on each word in the string.

W:SEP:
     Like w, but words are considered to be the parts of the string that are separated by SEP.  Delimiters are handled as in F above.

s/L/R[/]
     Substitute R for L.

     Unless preceded by a g, the substitution is done only for the first string that matches L.

     The left-hand side of substitutions are not regular expressions, but character strings.  Any character can be used as the delimiter in place of /.  A backslash quotes the delimiter character.  The character &, in the right-hand side, is replaced by the text from the left-hand side.  The & can be quoted with a backslash.  A null L uses the previous string either from a L or from a contextual scan string S from !?S.  You can omit the rightmost delimiter if a newline immediately follows R; the rightmost ? in a context scan can similarly be omitted.

By default, a history reference with no event specification refers to the same line as the last history reference on that command line, unless it is the first history reference in a command.  In that case, a history reference with no event specification always refers to the previous command.  However, if the option CSH_JUNKIE_HISTORY is set, then a history reference with no event specification will ALWAYS refer to the previous command.  For example, !!:1 will always refer to the first word of the previous command and !!$ will always refer to the last word of the previous command.  If CSH_JUNKIE_HISTORY is set, then !:1 and !$ will function in the same manner as !!:1 and !!$, respectively. However, if CSH_JUNKIE_HISTORY is unset, then !:1 and !$ will refer to the first and last words respectively of the last command referenced on the current command line.  However, if they are the first history reference on the command line, then they refer to the previous command.

The character sequence ^foo^bar repeats the last command, replacing the string foo with the string bar.

If the shell encounters the character sequence !" in the input, the history mechanism is temporarily disabled until the current list is fully parsed.  The !" is removed from the input, and any subsequent ! characters have no special significance.

A less convenient but more comprehensible form of command history support is provided by the fc builtin (see Shell Builtin Commands).

Arithmetic Evaluation
*********************

An ability to perform integer arithmetic is provided with the builtin let.  Evaluations are performed using long arithmetic. Constants are of the form [BASE#]N where BASE is a decimal number between two and thirty-six representing the arithmetic base and N is a number in that base (for example, 16#ff is 255 in hexadecimal).  If BASE is omitted then base 10 is used.  For backwards compatibility the form [16]ff is also accepted.

An arithmetic expression uses nearly the same syntax, precedence, and associativity of expressions in C.  The following operators are supported (listed in decreasing order of precedence):

+ - ! ~ ++ --
     Unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement

&
     Logical AND

^
     Logical XOR

|
     Logical OR

* / % **
     Multiplication, division, remainder, exponentiation

+ -
     Addition, subtraction

<< >>
     Logical shift left, shift right

< > <= >=
     Comparison

== !=
     Equality and inequality

&&
     Boolean AND

|| ^^
     Boolean OR, XOR

? :
     Ternary operator

= += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
     Assignment

,
     Comma operator

The operators &&, ||, &&=, and ||= are short-circuiting, and only one of the latter two expressions in a ternary operator is evaluated.  Note the precedence of the logical AND, OR, and XOR operators.

An expression of the form #\x where x is any character gives the ASCII value of this character.  An expression of the form #foo gives the ASCII value of the first character of the value of the parameter foo.

Named parameters can be referenced by name within an arithmetic expression without using the parameter substitution syntax, but if it is an array with a subscript the leading $ is needed.

An internal integer representation of a named parameter can be specified with the integer builtin.  Arithmetic evaluation is performed on the value of each assignment to a named parameter declared integer in this manner.

Since many of the arithmetic operators require quoting, an alternative form of the let command is provided.  For any command which begins with a ((, all the characters until a matching )) are treated as a quoted expression.  More precisely, (( ... )) is equivalent to let "...".

Conditional Expressions
***********************

A conditional expression is used with the [[ compound command to test attributes of files and to compare strings.  Each expression can be constructed from one or more of the following unary or binary expressions:

-a FILE
     True if FILE exists.

-b FILE
     True if FILE exists and is a block special file.

-c FILE
     True if FILE exists and is a character special file.

-d FILE
     True if FILE exists and is a directory.

-e FILE
     True if FILE exists.

-f FILE
     True if FILE exists and is an ordinary file.

-g FILE
     True if FILE exists and has its setgid bit set.

-h FILE
     True if FILE exists and is a symbolic link.

-k FILE
     True if FILE exists and has its sticky bit set.

-n STRING
     True if length of STRING is non-zero.

-o OPTION
     True if option named OPTION is on.

-p FILE
     True if FILE exists and is a FIFO special file or a pipe.

-r FILE
     True if FILE exists and is readable by the current process.

-s FILE
     True if FILE exists and has size greater than zero.

-t FD
     True if file descriptor number FD is open and associated with a terminal device (note: FD is not optional).

-u FILE
     True if FILE exists and has its setuid bit set.

-w FILE
     True if FILE exists and is writable by current process.

-x FILE
     True if FILE exists and is executable by current process.  If FILE exists and is a directory, then the current process has permission to search in the directory.

-z STRING
     True if length of STRING is zero.

-L FILE
     True if FILE exists and is a symbolic link.

-O FILE
     True if FILE exists and is owned by the effective user id of this process.

-G FILE
     True if FILE exists and its group matches the effective group id of this process.

-S FILE
     True if FILE exists and is a socket.

FILE1 -nt FILE2
     True if FILE1 exists and is newer than FILE2.

FILE1 -ot FILE2
     True if FILE1 exists and is older than FILE2.

FILE1 -ef FILE2
     True if FILE1 and FILE2 exist and refer to the same file.

STRING = PATTERN
     True if STRING matches PATTERN.

STRING != PATTERN
     True if STRING does not match PATTERN.

STRING1 < STRING2
     True if STRING1 comes before STRING2 based on ASCII value of their characters.

STRING1 > STRING2
     True if STRING1 comes after STRING2 based on ASCII value of their characters.

EXP1 -eq EXP2
     True if EXP1 is equal to EXP2.

EXP1 -ne EXP2
     True if EXP1 is not equal to EXP2.

EXP1 -lt EXP2
     True if EXP1 is less than EXP2.

EXP1 -gt EXP2
     True if EXP1 is greater than EXP2.

EXP1 -le EXP2
     True if EXP1 is less than or equal to EXP2.

EXP1 -ge EXP2
     True if EXP1 is greater than or equal to EXP2.

( EXP )
     True if EXP is true.

! EXP
     True if EXP is false.

EXP1 && EXP2
     True if EXP1 and EXP2 are both true.

EXP1 || EXP2
     True if either EXP1 or EXP2 is true.

In each of the above expressions, if FILE is of the form /dev/fd/N, where N is an integer, then the test is applied to the open file whose descriptor number is N, even if the underlying system does not support the /dev/fd directory.

Zsh Line Editor
***************

If the ZLE option is set (it is by default) and the shell input is attached to the terminal, the user is allowed to edit command lines.

There are two display modes.  The first, multiline mode, is the default. It only works if the TERM parameter is set to a valid terminal type that can move the cursor up.  The second, single line mode, is used if TERM is invalid or incapable of moving the cursor up, or if the SINGLE_LINE_ZLE option is set.  This mode is similar to ksh, and uses no termcap sequences.  If TERM is emacs, the ZLE option will be unset by the shell.

Command bindings may be set using the bindkey builtin.  There are two keymaps---the main keymap and the alternate keymap.  The alternate keymap is bound to vi command mode.  The main keymap is bound to emacs mode by default.  To bind the main keymap to vi insert mode, use bindkey -v.  However, if either of the VISUAL or EDITOR environment variables contains the string vi when the shell starts up the main keymap will be bound to vi insert mode by default.

The following is a list of all the key commands and their default bindings in emacs and vi command mode.

Movement
========

vi-backward-blank-word (unbound) (B)
     Move backward one word, where a word is defined as a series of non-blank characters.

backward-char (^B ESC-[D) (unbound)
     Move backward one character.

vi-backward-char (unbound) (h)
     Move backward one character, without changing lines.

backward-word (ESC-B ESC-b) (unbound)
     Move to the beginning of the previous word.

emacs-backward-word
     Move to the beginning of the previous word.

vi-backward-word (unbound) (b)
     Move to the beginning of the previous word, vi-style.

beginning-of-line (^A) (0)
     Move to the beginning of the line.  If already at the beginning of the line, move to the beginning of the previous line, if any.

vi-beginning-of-line
     Move to the beginning of the line, without changing lines.

end-of-line (^E)
     Move to the end of the line.  If already at the end of the line, move to the end of the next line, if any.

vi-end-of-line (unbound) ($)
     Move to the end of the line.

vi-forward-blank-word (unbound) (W)
     Move forward one word, where a word is defined as a series of non-blank characters.

vi-forward-blank-word-end (unbound) (E)
     Move to the end of the current word, or, if at the end of the current word, to the end of the next word, where a word is defined as a series of non-blank characters.

forward-char (^F ESC-[C)
     Move forward one character.

vi-forward-char (unbound) (SPACE l)
     Move forward one character.

vi-find-next-char (^X^F) (f)
     Read a character from the keyboard, and move to the next occurrence of it in the line.

vi-find-next-char-skip (unbound) (t)
     Read a character from the keyboard, and move to the position just before the next occurrence of it in the line.

vi-find-prev-char (unbound) (F)
     Read a character from the keyboard, and move to the previous occurrence of it in the line.

vi-find-prev-char-skip (unbound) (T)
     Read a character from the keyboard, and move to the position just after the previous occurrence of it in the line.

vi-first-non-blank (unbound) (^)
     Move to the first non-blank character in the line.

vi-forward-word (unbound) (w)
     Move forward one word, vi-style.

forward-word (ESC-F ESC-f) (unbound)
     Move to the beginning of the next word.  The editor's idea of a word is specified with the WORDCHARS parameter.

emacs-forward-word
     Move to the end of the next word.

vi-forward-word-end (unbound) (e)
     Move to the end of the next word.

vi-goto-column (ESC-|) (|)
     Move to the column specified by the numeric argument.

vi-goto-mark (unbound) (`)
     Move to the specified mark.

vi-goto-mark-line (unbound) (')
     Move to the beginning of the line containing the specified mark.

vi-repeat-find (unbound) (;)
     Repeat the last vi-find command.

vi-rev-repeat-find (unbound) (,)
     Repeat the last vi-find command in the opposite direction.

History Control
===============

beginning-of-buffer-or-history (ESC-<)
     Move to the beginning of the buffer, or if already there, move to the first event in the history list.

beginning-of-line-hist
     Move to the beginning of the line.  If already at the beginning of the buffer, move to the previous history line.

beginning-of-history
     Move to the first event in the history list.

down-line-or-history (^N ESC-[B) (+ j)
     Move down a line in the buffer, or if already at the bottom line, move to the next event in the history list.

down-line-or-search
     Move down a line in the buffer, or if already at the bottom line, search forward in the history for a line beginning with the first word in the buffer.

down-history (unbound) (^N)
     Move to the next event in the history list.

history-beginning-search-backward
     Search backward in the history for a line beginning with the current line up to the cursor.  This leaves the cursor in its original position.

end-of-buffer-or-history (ESC->)
     Move to the end of the buffer, or if already there, move to the last event in the history list.

end-of-line-hist
     Move to the end of the line.  If already at the end of the buffer, move to the next history line.

end-of-history
     Move to the last event in the history list.

vi-fetch-history (unbound) (G)
     Fetch the history line specified by the numeric argument.

history-incremental-search-backward (^R ^Xr)
     Search backward incrementally for a specified string.  The string may begin with ^ to anchor the search to the beginning of the line. A restricted set of editing functions is available in the mini-buffer. An interrupt signal, as defined by the stty setting, will stop the search and go back to the original line.  An undefined key will have the same effect.  The supported functions are: backward-delete-char, quoted-insert, accept-and-hold, accept-and-infer-next-history, accept-line and accept-line-and-down-history; magic-space just inserts a space.  Any string that is bound to an out-string (via bindkey -s) will behave as if out-string were typed directly.  Typing the binding of history-incremental-search-backward will get the next occurrence of the contents of the mini-buffer.  Typing the binding of history-incremental-search-forward inverts the sense of the search.  The direction of the search is indicated in the mini-buffer. Any multi-character string that is not bound to one of the above functions will beep and interrupt the search, leaving the last found line in the buffer.  Any single character that is not bound to one of the above functions, or self-insert or self-insert-unmeta, will have the same effect but the function will be executed.

history-incremental-search-forward (^S ^Xs)
     Search forward incrementally for a specified string.  The string may begin with ^ to anchor the search to the beginning of the line. The functions available in the mini-buffer are the same as for history-incremental-search-backward.

history-search-backward (ESC-P ESC-p) (K)
     Search backward in the history for a line beginning with the first word in the buffer.

vi-history-search-backward (unbound) (/)
     Search backward in the history for a specified string.  The string may begin with ^ to anchor the search to the beginning of the line. A restricted set of editing functions is available in the mini-buffer. An interrupt signal, as defined by the stty setting, will stop the search, as will a character bound to vi-cmd-mode.  The functions available in the mini-buffer are: accept-line, backward-delete-char, vi-backward-delete-char and quoted-insert.  Any string that is bound to an out-string (via bindkey -s) will behave as if out-string were typed directly.  Any other character that is not bound to self-insert or self-insert-unmeta will beep and be ignored.  If the function is called from vi command mode, the bindings of vi insert mode will be used.

history-search-forward (ESC-N ESC-n) (J)
     Search forward in the history for a line beginning with the first word in the buffer.

vi-history-search-forward (unbound) (?)
     Search forward in the history for a specified string.  The string may begin with ^ to anchor the search to the beginning of the line. The functions available in the mini-buffer are the same as for vi-history-search-backward.

infer-next-history (^X^N)
     Search in the history for a line matching the current one and fetch the event following it.

insert-last-word (ESC-_ ESC-.)
     Insert the last word from the previous history event at the cursor position.

vi-repeat-search (unbound) (n)
     Repeat the last vi history search.

vi-rev-repeat-search (unbound) (N)
     Repeat the last vi history search, but in reverse.

toggle-literal-history (ESC-R ESC-r)
     Toggle between literal and lexical history.  The default is lexical history unless the HIST_LIT option is set.

up-line-or-history (^P ESC-[A) (- k)
     Move up a line in the buffer, or if already at the top line, move to the previous event in the history list.

up-line-or-search
     Move up a line in the buffer, or if already at the top line, search backward in the history for a line beginning with the first word in the buffer.

up-history (unbound) (^P)
     Move to the previous event in the history list.

history-beginning-search-forward
     Search forward in the history for a line beginning with the current line up to the cursor.  This leaves the cursor at its original position.

Modifying Text
==============

vi-add-eol (unbound) (A)
     Move to the end of the line and enter insert mode.

vi-add-next (unbound) (a)
     Move forward one character and enter insert mode.

backward-delete-char (^H ^?) (^?)
     Delete the character behind the cursor.

vi-backward-delete-char (unbound) (X)
     Delete the character behind the cursor, without changing lines.

backward-delete-word
     Delete the word behind the cursor.

backward-kill-line
     Kill from the beginning of the line to the cursor position.

backward-kill-word (^W ESC-^H ESC-^?)
     Kill the word behind the cursor.

vi-backward-kill-word (unbound) (^W)
     Kill the word behind the cursor.

capitalize-word (ESC-C ESC-c)
     Capitalize the current word and move past it.

vi-change (unbound) (c)
     Read a movement command from the keyboard, and kill from the cursor position to the endpoint of the movement.  Then enter insert mode.  If the command is vi-change, kill the current line.

vi-change-eol (unbound) (C)
     Kill to the end of the line and enter insert mode.

vi-change-whole-line (unbound) (S s)
     Kill the current line and enter insert mode.

copy-region-as-kill (ESC-W ESC-w)
     Copy the area from the cursor to the mark to the kill buffer.

copy-prev-word (ESC-^_)
     Duplicate the word behind the cursor.

vi-delete (unbound) (d)
     Read a movement command from the keyboard, and kill from the cursor position to the endpoint of the movement.  If the command is vi-delete, kill the current line.

delete-char (unbound) (x)
     Delete the character under the cursor.

vi-delete-char (unbound) (x)
     Delete the character under the cursor.

delete-word (ESC-D ESC-d)
     Delete the current word.

down-case-word (ESC-L ESC-l)
     Convert the current word to all lowercase and move past it.

kill-word
     Kill the current word.

gosmacs-transpose-chars
     Exchange the two characters behind the cursor.

vi-indent (unbound) (>)
     Indent a number of lines.

vi-insert (unbound) (i)
     Enter insert mode.

vi-insert-bol (unbound) (I)
     Move to the beginning of the line and enter insert mode.

vi-join (^X^J)
     Join the current line with the next one.

kill-line (^K) (D)
     Kill from the cursor to the end of the line.

kill-region
     Kill from the cursor to the mark.

kill-buffer (^X^K) (^U)
     Kill the entire buffer.

kill-whole-line (^U) (unbound)
     Kill the current line.

vi-match-bracket (^X^B) (%)
     Move to the bracket character (one of {}, (), or []) that matches the one under the cursor.

vi-open-line-above (unbound) (O)
     Open a line above the cursor and enter insert mode.

vi-open-line-below (unbound) (o)
     Open a line below the cursor and enter insert mode.

vi-oper-swap-case
     Read a movement command from the keyboard, and swap the case of all characters from the cursor position to the endpoint of the movement.  If the movement command is vi-oper-swap-case, swap the case of all characters on the current line.

overwrite-mode (^X^O)
     Toggle between overwrite mode and insert mode.

vi-put-after (unbound) (p)
     Insert the contents of the kill buffer after the cursor.

quoted-insert (^V)
     Insert the next character typed into the buffer literally.

quote-line (ESC-')
     Quote the current line; that is, put a ' character at the beginning and the end, and convert all ' characters to \'.

quote-region (ESC-")
     Quote the region from the cursor to the mark.

vi-replace (unbound) (R)
     Enter overwrite mode.

vi-repeat-change (unbound) (.)
     Repeat the last vi mode text modification.

vi-replace-chars (unbound) (r)
     Replace the character under the cursor with a character read from the keyboard.

self-insert (printable characters)
     Put a character in the buffer at the cursor position.

self-insert-unmeta (ESC-^I ESC-^J ESC-^M)
     Put a character in the buffer after stripping the meta bit and converting ^M to ^J.

vi-substitute (unbound) (s)
     Substitute the next character(s).

vi-swap-case (unbound) (~)
     Swap the case of the character under the cursor and move past it.

transpose-chars (^T)
     Exchange the two characters to the left of the cursor if at end of line, else exchange the character under the cursor with the character to the left.

transpose-words (ESC-T ESC-t)
     Exchange the current word with the one before it.

vi-unindent (unbound) (<)
     Unindent a number of lines.

up-case-word (ESC-U ESC-u)
     Convert the current word to all caps and move past it.

yank (^Y) (P)
     Insert the contents of the kill buffer at the cursor position.

yank-pop (ESC-y) (unbound)
     Remove the text just yanked, rotate the kill-ring, and yank the new top. Only works following yank or yank-pop.

vi-yank (unbound) (y)
     Read a movement command from the keyboard, and copy the region from the cursor position to the endpoint of the movement into the kill buffer. If the command is vi-yank, copy the current line.

vi-yank-eol (unbound) (Y)
     Copy the region from the cursor position to the end of the line into the kill buffer.

Arguments
=========

digit-argument (ESC-0...ESC-9) (0-9)
     Start a new numeric argument, or add to the current one.

neg-argument (ESC--) (unbound)
     Changes the sign of the following argument.

universal-argument
     Multiply the argument of the next command by 4.

Completion
==========

accept-and-menu-complete
     In a menu completion, insert the current completion into the buffer, and advance to the next possible completion.

complete-word (unbound) (\)
     Attempt completion on the current word.

delete-char-or-list (^D)
     Delete the character under the cursor.  If the cursor is at the end of the line, list possible completions for the current word.

execute-named-cmd (ESC-x)
     Read the name of a editor command and execute it.  A restricted set of editing functions is available in the mini-buffer.  An interrupt signal, as defined by the stty setting, will abort the function.  The allowed functions are: backward-delete-char, vi-backward-delete-char, kill-region (kills the last word), backward-kill-word, vi-backward-kill-word, kill-whole-line, vi-kill-line, backward-kill-line and accept-line.  The SPACE and TAB keys, if not bound to one of these functions, will complete the name and then list the possibilities.

execute-last-named-cmd (ESC-z)
     Redo the last function executed with execute-named-cmd.

expand-cmd-path
     Expand the current command to its full pathname.

expand-or-complete (TAB) (TAB ^X)
     Attempt shell expansion on the current word.  If that fails, attempt completion.

expand-or-complete-prefix
     Attempt shell expansion on the current word up to the cursor.

expand-history (ESC-SPACE ESC-!)
     Perform history expansion on the edit buffer.

expand-word (^X*)
     Attempt shell expansion on the current word.

list-choices (ESC-^D) (^D=)
     List possible completions for the current word.

list-expand (^Xg ^XG) (^G)
     List the expansion of the current word.

magic-space
     Perform history expansion and insert a space into the buffer.  This is intended to be bound to SPACE.

menu-complete
     Like complete-word, except that menu completion is used. See Options, for the MENU_COMPLETE option.

menu-expand-or-complete
     Like expand-or-complete, except that menu completion is used.

reverse-menu-complete
     See Options, for the MENU_COMPLETE option.

Miscellaneous
=============

accept-and-hold (ESC-A ESC-a)
     Push the contents of the buffer on the buffer stack and execute it.

accept-and-infer-next-history
     Execute the contents of the buffer.  Then search the history list for a line matching the current one and push the event following onto the buffer stack.

accept-line (^J ^M)
     Execute the contents of the buffer.

accept-line-and-down-history (^O)
     Execute the current line, and push the next history event on the the buffer stack.

vi-cmd-mode (^X^V) (^[)
     Enter command mode; that is, use the alternate keymap.  Yes, this is bound by default in emacs mode.

vi-caps-lock-panic (unbound) (H K)
     Hang until any lowercase key is pressed.  This is for vi users without the mental capacity to keep track of their caps lock key (like the author).

clear-screen (^L ESC-^L)
     Clear the screen and redraw the prompt.

exchange-point-and-mark (^X^X)
     Exchange the cursor position with the position of the mark.

get-line (ESC-G ESC-g)
     Pop the top line off the buffer stack and insert it at the cursor position.

pound-insert (unbound) (#)
     If there is no # character at the beginning of the current line, add one.  If there is one, remove it.  In either case, accept the current line.  The INTERACTIVE_COMMENTS option must be set for this to have any usefulness.

push-input
     Push the entire current multiline construct onto the buffer stack and return to the top-level (PS1) prompt.  If the current parser construct is only a single line, this is exactly like push-line. Next time the editor starts up or is popped with get-line, the construct will be popped off the top of the buffer stack and loaded into the editing buffer.

push-line (^Q ESC-Q ESC-q)
     Push the current buffer onto the buffer stack and clear the buffer. Next time the editor starts up, the buffer will be popped off the top of the buffer stack and loaded into the editing buffer.

push-line-or-edit
     At the top-level (PS1) prompt, equivalent to push-line. At a secondary (PS2) prompt, move the entire current multiline construct into the editor buffer.  The latter is equivalent to push-line followed by get-line.

redisplay (unbound) (^R)
     Redisplays the edit buffer.

run-help (ESC-H ESC-h)
     Push the buffer onto the buffer stack, and execute the command run-help CMD, where CMD is the current command. run-help is normally aliased to man.

send-break (^C)
     Abort the current editor function, e.g. execute-named-command, or the editor itself, e.g. if you are in vared.  Otherwise abort the parsing of the current line.

vi-set-buffer (unbound) (")
     Specify a buffer to be used in the following command.

vi-set-mark (unbound) (m)
     Set the specified mark at the cursor position.

set-mark-command (^@)
     Set the mark at the cursor position.

spell-word (ESC-$ ESC-S ESC-s)
     Attempt spelling correction on the current word.

undefined-key
     Beep.

undo (^_ ^X^U ^Xu (u)
     Incrementally undo the last text modification.

which-command (ESC-?)
     Push the buffer onto the buffer stack, and execute the command which-command CMD, where CMD is the current command. which-command is normally aliased to whence.

Parameters
**********

A parameter has a name, a value, and a number of attributes.  A name may be any sequence of alphanumeric characters and _'s, or the single characters *, @, #, ?, -, $, or !.  The value may be either a scalar (a string), an integer, or an array.  To assign a scalar or integer value to a parameter, use the typeset builtin.  To assign an array value, use set -A NAME VALUE ....  The value of a parameter may also be assigned by writing:

NAME=VALUE ...

If the integer attribute, -i, is set for NAME, the VALUE is subject to arithmetic evaluation.

Array Parameters
================

The value of an array parameter may be assigned by writing:

NAME=(VALUE ...) ...

Individual elements of an array may be selected using a subscript.  A subscript of the form [EXP] selects the single element EXP, where EXP is an arithmetic expression.  The elements are numbered beginning with 1.  A subscript of the form [*] or [@] evaluates to all elements of an array; there is no difference between the two except when they appear within double quotes. "$foo[*]" evaluates to "$foo[1] $foo[2] ...", while "$foo[@]" evaluates to "$foo[1]" "$foo[2]", etc. A subscript of the form [EXP1,EXP2] selects all elements in the range EXP1 to EXP2, inclusive.  If one of the subscripts evaluates to a negative number, say -N, then the N'th element from the end of the array is used.  Thus $foo[-3] is the third element from the end of the array foo, and $foo[1,-1] is the same as $foo[*].

Subscripting may also be performed on non-array values, in which case the subscripts specify a substring to be extracted.  For example, if FOO is set to foobar, then echo $FOO[2,5] prints ooba.

If a subscript is used on the left side of an assignment the selected range is replaced by the expression on the right side.

If the opening bracket or the comma is directly followed by an opening parenthesis the string up to the matching closing parenthesis is considered to be a list of flags.  The possible flags are:

e
     The argument is expanded using full shell expansion first.

w
     If the parameter subscripted is a scalar, make subscription work on a per-word basis instead of on a per-character basis.

s:STRING:
     Defines the STRING that separates words (for use with the w flag).

r
     The subscript is taken as a pattern, and the result is the first matching array element, substring, or word (if the parameter is an array, scalar, or a scalar and the w flag is given, respectively).  Note that this is like giving a number; $foo[(r)??,3] and $foo[(r)??,(r)f*] work.

R
     Like r, but returns the last match.

i
     Like r, but returns the index of the match.  This must not be combined with a second argument.

I
     Like i, but returns the index of the last match.

n:EXPR:
     If combined with r, R, i, or I, makes them return the N'th or N'th last match (assuming EXPR evaluates to N).

Positional Parameters
=====================

Positional parameters are set by the shell on invocation, by the set builtin, or by direct assignment.  The parameter N, where N is a number, is the N'th positional parameter.  The parameters *, @, and argv are arrays containing all the positional parameters; thus argv[N], is equivalent to simply N.

Parameters Set By The Shell
===========================

The following parameters are automatically set by the shell:

!
     The process id of the last background command invoked.

#
     The number of positional parameters in decimal.

ARGC
     Same as #.

$
     The process id of this shell.

-
     Flags supplied to the shell on invocation or by the set or setopt commands.

*
     An array containing the positional parameters.

argv
     Same as *.

@
     Same as argv[@].

?
     The exit value returned by the last command.

status
     Same as ?.

_
     The last argument of the previous command.  Also, this parameter is set in the environment of every command executed to the full pathname of the command.

EGID
     The effective group id of the shell process.

EUID
     The effective user id of the shell process.

ERRNO
     The value of errno as set by the most recently failed system call.  This value is system dependent and is intended for debugging purposes.

GID
     The group id of the shell process.

HOST
     The current hostname.

HOSTTYPE
     A string corresponding to the type of the host the shell is running on.

LINENO
     The line number of the current line within the current script being executed.

OLDPWD
     The previous working directory.

OPTARG
     The value of the last option argument processed by the getopts command.

OPTIND
     The index of the last option argument processed by the getopts command.

PPID
     The process id of the parent of the shell.

PWD
     The present working directory.

RANDOM
     A random integer from 0 to 32767, newly generated each time this parameter is referenced.  The random number generator can be seeded by assigning a numeric value to RANDOM.

SECONDS
     The number of seconds since shell invocation.  If this parameter is assigned a value, then the value returned upon reference will be the value that was assigned plus the number of seconds since the assignment.

SHLVL
     Incremented by one each time a new shell is started.

signals
     An array containing the names of the signals.

TTY
     The name of the tty associated with the shell, if any.

UID
     The user id of the shell process.

USERNAME
LOGNAME
     The username corresponding to the user id of the shell process.

VERSION
     The version number of this zsh.

Parameters Used By The Shell
============================

The following parameters are used by the shell:

ARGV
     If exported, its value is used as argv[0] of external commands.  Usually used in constructs like ARGV0=emacs nethack.

BAUD
     The baud rate of the current connection.  Used by the line editor update mechanism to compensate for a slow terminal by delaying updates until necessary.  This may be profitably set to a lower value in some circumstances, e.g. for slow modems dialing into a communications server which is connected to a host via a fast link; in this case, this variable would be set by default to the speed of the fast link, and not the modem.  This parameter should be set to the baud rate of the slowest part of the link for best performance.  The compensation mechanism can be turned off by setting the variable to zero.

cdpath (CDPATH)
     An array (colon-separated list) of directories specifying the search path for the cd command.

COLUMNS
     The number of columns for this terminal session.  Used for printing select lists and for the line editor.

DIRSTACKSIZE
     The maximum size of the directory stack.  If the stack gets larger than this, it will be truncated automatically.  This is useful with the AUTO_PUSHD option.

FCEDIT
     The default editor for the fc builtin.

fignore (FIGNORE)
     An array (colon-separated list) containing the suffixes of files to be ignored during filename completion.

fpath (FPATH)
     An array (colon-separated list) of directories specifying the search path for function definitions.  This path is searched when a function with the -u attribute is referenced.  If an executable file is found, then it is read and executed in the current environment.

HISTCHARS
     Three characters used by the shell's history and lexical analysis mechanism.  The first character signals the start of a history substitution (default !).  The second character signals the start of a quick history substitution (default ^).  The third character is the comment character (default #).

HISTFILE
     The file to save the history in when an interactive shell exits.  If unset, the history is not saved.

HISTSIZE
     The maximum size of the history list.

HOME
     The default argument for the cd command.

IFS
     Internal field separators, normally space, tab, and newline, that are used to separate words which result from command or parameter substitution and words read by the read builtin.

KEYTIMEOUT
     The time the shell waits, in hundredths of seconds, for another key to be pressed when reading bound multi-character sequences.

LINES
     The number of lines for this terminal session.  Used for printing select lists and for the line editor.

LISTMAX
     In the line editor, the number of filenames to list without asking first.  If set to zero, the shell asks only if the listing would scroll off the screen.

LITHISTSIZE
     The maximum size of the literal history list (before history expansion).

LOGCHECK
     The interval in seconds between checks for login/logout activity using the watch parameter.

MAIL
     If this parameter is set and mailpath is not set, the shell looks for mail in the specified file.

MAILCHECK
     The interval in seconds between checks for new mail.

mailpath (MAILPATH)
     An array (colon-separated list) of filenames to check for new mail. Each filename can be followed by a ? and a message that will be printed.  The sequence $_ in the message will be replaced by the name of the mail file.  The default message is You have new mail.  If an element is a directory instead of a file the shell will recursively check every file in every subdirectory of the element.

manpath (MANPATH)
     An array (colon-separated list) whose value is not used by the shell. The manpath array can be useful, however, since setting it also sets MANPATH, and vice versa.

NULLCMD
     The command name to assume if a redirection is specified with no command.  Defaults to cat.  For sh/ksh-like behavior, change this to :.  For csh-like behavior, unset this parameter; the shell will print an error message if null commands are entered.

path (PATH)
     An array (colon-separated list) of directories to search for commands. When this parameter is set, each directory is scanned and all files found are put in a hash table.

POSTEDIT
     This string is output whenever the line editor exits.  It usually contains termcap strings to reset the terminal.

PROMPT
     The primary prompt string, printed before a command is read; the default is %m%# .  If the escape sequence takes an optional integer, it should appear between the % and the next character of the sequence.  The following escape sequences are recognized:

     %d
     %/
          Present working directory ($PWD).

     %~
          $PWD.  If it has a named directory as its prefix, that part is replaced by a ~ followed by the name of the directory.  If it starts with $HOME, that part is replaced by a ~.

     %c
     %.
     %C
          Trailing component of $PWD.  An integer may follow the % to get more than one component.  Unless %C is used, tilde expansion is performed first.

     !
     %h
     %!
          Current history event number

     %M
          The full machine hostname.

     %m
          The hostname up to the first ..  An integer may follow the % to specify how many components of the hostname are desired.

     %S (%s)
          Start (stop) standout mode.

     %U (%u)
          Start (stop) underline mode.

     %B (%b)
          Start (stop) boldface mode.

     %t
     %@
          Current time of day, in 12-hour, am/pm format.

     %T
          Current time of day, in 24-hour format.

     %*
          Current time of day in 24-hour format, with seconds.

     %n
          $USERNAME.

     %w
          The date in day-dd format.

     %W
          The date in mm/dd/yy format.

     %D
          The date in yy-mm-dd format.

     %D{STRING}
          STRING is formatted using the strftime function.  See strftime(3) for more details, if your system has it.

     %l
          The line (tty) the user is logged in on.

     %?
          The return code of the last command executed just before the prompt.

     %_
          The status of the parser, i.e. the shell constructs (like if and for) that have been started on the command line.  If given an integer number, that many strings will be printed.

     E
          Clears to end of screen.  Useful with ALWAYS_LAST_PROMPT set.

     %#
          A # if the shell is running as root, a % if not. Equivalent to %(#.#.%%)

     %v
          The value of the first element of the psvar array parameter. Following the % with an integer gives that element of the array.

     %{...%}
          Include a string as a literal escape sequence.  The string within the braces should not change the cursor position.

     %(x.TRUE-TEXT.FALSE-TEXT)
          Specifies a ternary expression.  The character following the x is arbitrary; the same character is used to separate the text for the true result from that for the false result.  Both the separator and the right parenthesis may be escaped with a backslash.  TRUE-TEXT and FALSE-TEXT may both contain arbitrarily-nested escape sequences, including further ternary expressions.  The left parenthesis may be preceded or followed by a positive integer N, which defaults to zero.  The text character x may be any of the following:

          c
          .
          ~
               True if the current path, with prefix replacement, has at least N elements.

          /
          C
               True if the current absolute path has at least N elements.

          t
               True if the time in minutes is equal to N.

          T
               True if the time in hours is equal to N.

          d
               True if the day of the month is equal to N.

          D
               True if the month is equal to N (January = 0).

          w
               True if the day of the week is equal to N (Sunday = 0).

          ?
               True if the exit status of the last command was N.

          #
               True if the effective uid of the current process is N.

          g
               True if the effective gid of the current process is N.

          L
               True if the SHLVL parameter is at least N.

          S
               True if the SECONDS parameter is at least N.

          v
               True if the array psvar has at least N elements.

          _
               True if at least N shell constructs were started.

PROMPT2
     The secondary prompt, printed when the shell needs more information to complete a command.  Recognizes the same escape sequences as PROMPT.  The default is > .

PROMPT3
     Selection prompt used within a select loop.  Recognizes the same escape sequences as PROMPT.  The default is ?# .

PROMPT4
     The execution trace prompt.  Default is + .

PS1
PS2
PS3
PS4
     Same as PROMPT, PROMPT2, PROMPT3, and PROMPT4, respectively.

psvar (PSVAR)
     An array (colon-separated list) whose first nine values can be used in PROMPT strings.  Setting psvar also sets PSVAR, and vice versa.

prompt
     Same as PROMPT.

READNULLCMD
     The command name to assume if a single input redirection is specified with no command.  Defaults to more.

REPORTTIME
     If nonzero, commands whose combined user and system execution times (measured in seconds) are greater than this value have timing statistics printed for them.

RPROMPT
RPS1
     This prompt is displayed on the right-hand side of the screen when the primary prompt is being displayed on the left.  This does not work if the SINGLE_LINE_ZLE option is set.  Recognizes the same escape sequences as PROMPT.

SAVEHIST
     The maximum number of history events to save in the history file.

SPROMPT
     The prompt used for spelling correction.  The sequence %R expands to the string which presumably needs spelling correction, and %r expands to the proposed correction.  All other PROMPT escapes are also allowed.

STTY
     If this parameter is set in a command's environment, the shell runs the stty command with the value of this parameter as arguments in order to set up the terminal before executing the command.  The modes apply only to the command, and are reset when it finishes or is suspended.  If the command is suspended and continued later with the fg or wait builtins it will see the modes specified by STTY, as if it were not suspended.  This (intentionally) does not apply if the command is continued via kill -CONT.  STTY is ignored if the command is run in the background, or if it is in the environment of the shell but not explicitly assigned to in the input line.  This avoids running stty at every external command by accidentally exporting it.  Also note that STTY should not be used for window size specifications; these will not be local to the command.

TIMEFMT
     The format of process time reports with the time keyword.  The default is %E real  %U user  %S system  %P %J.  Recognizes the following escape sequences:

     %U
          CPU seconds spent in user mode.

     %S
          CPU seconds spent in kernel mode.

     %E
          Elapsed time in seconds.

     %P
          The CPU percentage, computed as (%U+%S)/%E.

     %W
          Number of times the process was swapped.

     %X
          The average amount of (shared) text space used in Kbytes.

     %D
          The average amount of (unshared) data/stack space used in Kbytes.

     %K
          The total space used (%X+%D) in Kbytes.

     %M
          The maximum memory the process had in use at any time in Kbytes.

     %F
          The number of major page faults (page needed to be brought from disk).

     %R
          The number of minor page faults.

     %I
          The number of input operations.

     %O
          The number of output operations.

     %r
          The number of socket messages received.

     %s
          The number of socket messages sent.

     %k
          The number of signals received.

     %w
          Number of voluntary context switches (waits).

     %c
          Number of involuntary context switches.

     %J
          The name of this job.

TMOUT
     If this parameter is nonzero, the shell will terminate if a command is not entered within the specified number of seconds after issuing a prompt.

TMPPREFIX
     A pathname prefix which the shell will use for all temporary files.

watch (WATCH)
     An array (colon-separated list) of login/logout events to report.  If it contains the single word all, then all login/logout events are reported.  If it contains the single word notme, then all login/logout events are reported except for those originating from $USERNAME.  An entry in this list may consist of a username, an @ followed by a remote hostname, and a % followed by a line (tty).  Any or all of these components may be present in an entry; if a login/logout event matches all of them, it is reported.

WATCHFMT
     The format of login/logout reports if the watch parameter is set. Default is %n has %a %l from %m.  Recognizes the following escape sequences:

     %n
          The name of the user that logged in/out.

     %a
          The observed action, i.e. logged on or logged off.

     %l
          The line (tty) the user is logged in on.

     %M
          The full hostname of the remote host.

     %m
          The hostname up to the first ..  If only the IP address is available or the utmp field contains the name of an X-windows display, the whole name is printed.

          NOTE: The %m and %M escapes will work only if there is a host name field in the utmp on your machine.  Otherwise they are treated as ordinary strings.

     %S (%s)
          Start (stop) standout mode.

     %U (%u)
          Start (stop) underline mode.

     %B (%b)
          Start (stop) boldface mode.

     %t
     %@
          The time, in 12-hour, am/pm format.

     %T
          The time, in 24-hour format.

     %w
          The date in day-dd format.

     %W
          The date in mm/dd/yy format.

     %D
          The date in yy-mm-dd format.

     %(x:TRUE-TEXT:FALSE-TEXT)
          Specifies a ternary expression.  The character following the x is arbitrary; the same character is used to separate the text for the true result from that for the false result.  Both the separator and the right parenthesis may be escaped with a backslash.  Ternary expressions may be nested.

          The test character x may be any one of l, n, m, or M, which indicate a true result if the corresponding escape sequence would return a non-empty value; or it may be a, which indicates a true result if the watched user has logged in, or false if he has logged out.  Other characters evaluate to neither true nor false; the entire expression is omitted in this case.

          If the result is true, then the TRUE-TEXT is formatted according to the result above and printed, and the FALSE-TEXT is skipped. If false, the TRUE-TEXT is skipped, and the FALSE-TEXT is formatted and printed.  Either or both of the branches may be empty, but both separators must always be present.

WORDCHARS
     A list of nonalphanumeric characters considered part of a word by the line editor.

ZDOTDIR
     The directory to search for shell startup files (.zshrc, etc), if not $HOME.

Options
*******

The following options may be set upon invocation of the shell, or with the set or setopt builtins.  The names are case-insensitive and underscores are ignored, that is, allexport is equivalent to A_lleXP_ort.

ALL_EXPORT (-a)
     All parameters subsequently defined are automatically exported.

ALWAYS_LAST_PROMPT
     If unset, key functions that list completions try to return to the last prompt if given a numeric argument.  If set, these functions try to return to the last prompt if given no numeric argument.

ALWAYS_TO_END
     If a completion with the cursor in the word was started and it results in only one match, the cursor is placed at the end of the word.

APPEND_HISTORY
     If this is set, zsh sessions will append their history list to the history file, rather than overwrite it.  Thus, multiple parallel zsh sessions will all have their history lists added to the history file, in the order they are killed.  See Shell Builtin Commands, for the fc command.

AUTO_CD (-J)
     If a command is not in the hash table, and there exists an executable directory by that name, perform the cd command to that directory.

AUTO_LIST (-9)
     Automatically list choices on an ambiguous completion.

AUTO_MENU
     Automatically use menu completion after the second consecutive request for completion, for example by pressing the TAB key repeatedly. This option is overriden by MENU_COMPLETE.

AUTO_PARAM_KEYS
     If a parameter name was completed and the next character typed is one of those that have to come directly after the name (like }, :, etc.), they are placed there automatically.

AUTO_PUSHD (-N)
     Make cd act like pushd.

AUTO_REMOVE_SLASH
     When the last character resulting from a completion is a slash and the next character typed is a word delimiter, remove the slash.

AUTO_RESUME (-W)
     Treat single word simple commands without redirection as candidates for resumption of an existing job.

BGNICE (-6)
     Run all background jobs at a lower priority.  This option is set by default.

BRACE_CCL
     Allow brace expansions of the form {a-zA-Z}, etc.

CDABLE_VARS (-T)
     If the argument to a cd command (or an implied cd with the AUTO_CD option set) is not a directory, and does not begin with a slash, try to expand the expression as if it were preceded by a ~ see Filename Expansion.

CHASE_LINKS (-w)
     Resolve symbolic links to their true values.

COMPLETE_ALIASES
     If set, aliases on the command line are not internally substituted before completion is attempted.

COMPLETE_IN_WORD
     If unset, the cursor is moved to the end of the word if completion is started.  Otherwise it stays where it is and completion is done from both ends.

CORRECT (-0)
     Try to correct the spelling of commands.

CORRECT_ALL (-O)
     Try to correct the spelling of all arguments in a line.

CSH_JUNKIE_HISTORY
     A history reference without an event specifier will always refer to the previous command.

CSH_JUNKIE_LOOPS
     Allow loop bodies to take the form LIST; end instead of do LIST; done.

CSH_JUNKIE_QUOTES
     Complain if a quoted expression runs off the end of a line; prevent quoted expressions from containing unescaped newlines.

CSH_JUNKIE_TILDE
     Any unquoted = and ~ resulting from parameter substitution are eligible for file expansion.

CSH_NULL_GLOB
     If a pattern for filename generation has no matches, delete the pattern from the argument list; do not report an error unless all the patterns in a command have no matches.  Overrides NULL_GLOB.

ERR_EXIT (-e)
     If a command has a non-zero exit status, execute the ZERR trap, if set, and exit.

EXTENDED_GLOB
     Treat the # and ^ characters as part of patterns for filename generation, etc.

EXTENDED_HISTORY
     Save beginning and ending timestamps to the history file.  The format of these timestamps is :<BEGINNING TIME>:<ENDING TIME>:<COMMAND>.

GLOB_COMPLETE
     When the current word has a glob pattern, do not insert all the words resulting from the expansion but cycle through them like MENU_COMPLETE.  If no matches are found, a * is added to the end of the word, or inserted at the cursor if COMPLETE_IN_WORD is set, and completion is attempted again. Using patterns works not only for files but for all completions, such as options, user names, etc.

GLOB_DOTS (-4)
     Do not require a leading . in a filename to be matched explicitly.

HASH_CMDS
     Place the location of each command in the hash table the first time it is executed.  If this option is unset, no path hashing will be done at all.

HASH_DIRS
     Whenever a command is executed, hash the directory containing it, as well as all directories that occur earlier in the path.  Has no effect if HASH_CMDS is unset.

HASH_LIST_ALL
     Whenever a command completion is attempted, make sure the entire command path is hashed first.  This makes the first completion slower.

HIST_IGNORE_DUPS (-h)
     Do not enter command lines into the history list if they are duplicates of the previous event.

HIST_IGNORE_SPACE (-g)
     Do not enter command lines into the history list if they begin with a blank.

HIST_LIT (-j)
     Use literal (unparsed) versions of the history lines in the editor.

HIST_NO_STORE
     Remove the history (fc -l) command from the history when invoked.

HIST_VERIFY
     Whenever the user enters a line with history substitution, don't execute the line directly; instead, perform history substitution and reload the line into the editing buffer.

IGNORE_BRACES (-I)
     Do not perform brace expansion.

IGNORE_EOF (-7)
     Do not exit on end-of-file.  Require the use of exit or logout instead.

INTERACTIVE (-i)
     This is an interactive shell.

INTERACTIVE_COMMENTS (-k)
     Allow comments even in interactive shells.

KSH_OPTION_PRINT
     Alters the way options settings are printed.

LIST_AMBIGUOUS
     If this option is set completions are shown only if the completions don't have an unambiguous prefix or suffix that could be inserted in the command line.

LIST_TYPES (-X)
     When listing files that are possible completions, show the type of each file with a trailing identifying mark.

LOGIN (-l)
     This is a login shell.

LONG_LIST_JOBS (-R)
     List jobs in the long format by default.

MAIL_WARNING (-U)
     Print a warning message if a mail file has been accessed since the shell last checked.

MARK_DIRS (-8)
     Append a trailing / to all directory names resulting from filename generation (globbing).

MENU_COMPLETE (-Y)
     On an ambiguous completion, instead of listing possibilities or beeping, insert the first match immediately.  Then when completion is requested again, remove the first match and insert the second match, etc.  When there are no more matches, go back to the first one again. reverse-menu-complete may be used to loop through the list in the other direction.  This option overrides AUTO_MENU.

MONITOR (-m)
     Allow job control.  Set by default in interactive shells.

NO_BAD_PATTERN (-2)
     If a pattern for filename generation is badly formed, leave it unchanged in the argument list instead of printing an error.

NO_BANG_HIST (-K)
     Do not perform textual history substitution.  Do not treat the ! character specially.

NO_BEEP (-B)
     Do not beep.

NO_CLOBBER (-1)
     Prevents > redirection from truncating existing files.  >! may be used to truncate a file instead.  Also prevents >> from creating files.  >>! may be used instead.

NO_EQUALS
     Don't perform = filename substitution.

NO_EXEC (-n)
     Read commands and check them for syntax errors, but do not execute them.

NO_FLOW_CONTROL
     Disable output flow control via start/stop characters (usually assigned to ^S/^Q) in the shell's editor.

NO_GLOB (-F)
     Disable filename generation.

NO_HIST_BEEP
     Don't beep when an attempt is made to access a history entry which isn't there.

NO_HUP
     Don't send the HUP signal to running jobs when the shell exits.

NO_LIST_BEEP
     Don't beep on an ambiguous completion.

NO_NOMATCH (-3)
     If a pattern for filename generation has no matches, leave it unchanged in the argument list instead of printing an error.  This also applies to file expansion of an initial ~ or =.

NO_PROMPT_CR (-V)
     Don't print a carriage return just before printing a prompt in the line editor.

NO_RCS (-f)
     Source only the /etc/zshenv file. Do not source the .zshenv, /etc/zprofile, .zprofile, /etc/zshrc, .zshrc, /etc/zlogin, .zlogin, or .zlogout files.

NO_SHORT_LOOPS
     Disallow the short forms of for, select, if, and function constructs.

NOTIFY (-5)
     Report the status of background jobs immediately, rather than waiting until just before printing a prompt.

NO_UNSET (-u)
     Treat unset parameters as an error when substituting.

NULL_GLOB (-G)
     If a pattern for filename generation has no matches, delete the pattern from the argument list instead of reporting an error.  Overrides NO_NOMATCH.

NUMERIC_GLOBSORT
     If numeric filenames are matched by a filename generation pattern, sort the filenames numerically rather than lexicographically.

OVERSTRIKE
     Start up the line editor in overstrike mode.

PATH_DIRS (-Q)
     Perform a path search even on command names with slashes in them.  Thus if
     /usr/local/bin is in the user's path, and he types X11/xinit, the command /usr/local/bin/X11/xinit will be executed (assuming it exists).  This applies to the . builtin as well as to command execution.  Commands explicitly beginning with ./ or ../ are not subject to path search.

MAGIC_EQUAL_SUBST
     All unquoted arguments of the form IDENTIFIER=EXPRESSION have file expansion performed on EXPRESSION as if it were a parameter assignment, although the argument is not otherwise treated specially.

PRINT_EXIT_VALUE (-C)
     Print the exit value of programs with non-zero exit status.

PROMPT_SUBST
     Expressions like ${...}, $(...), and $[...] in prompts will be expanded.

PUSHD_IGNORE_DUPS
     Don't push multiple copies of the same directory onto the directory stack.

PUSHD_MINUS
     See Shell Builtin Commands, for the popd command.

PUSHD_SILENT (-E)
     Do not print the directory stack after pushd or popd.

PUSHD_TO_HOME (-D)
     Have pushd with no arguments act like pushd $HOME.

RC_EXPAND_PARAM (-P)
     See Parameter Expansion.

RC_QUOTES
     Allow the character sequence to signify a single quote within singly quoted strings.

REC_EXACT (-S)
     In completion, recognize exact matches even if they are ambiguous.

RM_STAR_SILENT (-H)
     Do not query the user before executing rm * or rm path/*.

SHIN_STDIN (-s)
     Read commands from the standard input.

SH_WORD_SPLIT (-y)
     See Parameter Expansion.

SINGLE_LINE_ZLE (-M)
     Use single-line command line editing instead of multi-line.

SUN_KEYBOARD_HACK (-L)
     If a line ends with a backquote, and there are an odd number of backquotes on the line, ignore the trailing backquote.  This is useful on some keyboards where the return key is too small, and the backquote key lies annoyingly close to it.

VERBOSE (-v)
     Print shell input lines as they are read.

XTRACE (-x)
     Print commands and their arguments as they are executed.

ZLE (-Z)
     Use the zsh line editor.

Shell Builtin Commands
**********************

. FILE [ ARG ... ]
     Read and execute commands from FILE in the current shell environment.  If FILE does not contain a slash, or if PATH_DIRS is set, the shell looks in the components of path to find the directory containing FILE.  Files in the current directory are not read unless . appears somewhere in path.  If any arguments ARG are given, they become the positional parameters; the old positional parameters are restored when the FILE is done executing.  The exit status is the exit status of the last command executed.

: [ ARG ... ]
     This command only expands parameters.  A zero exit code is returned.

alias [ -grm ] [ NAME[=VALUE] ] ...
     With no arguments, print the list of aliases in the form NAME=VALUE on the standard output.  For each NAME with a corresponding VALUE, define an alias with that value.  A trailing space in VALUE causes the next word to be checked for alias substitution.  If the -g flag is given, define a global alias; global aliases are expanded even if they do not occur in command position.  For each NAME with no VALUE, print the value of NAME, if any.  If only the -g or the -r flag is given only global or regular aliases are listed.  If the -m flag is given the arguments are taken as patterns (they should be quoted to preserve them from being interpreted as glob patterns) and the aliases matching these patterns are printed.  The exit status is nonzero if a NAME (with no VALUE) is given for which no alias has been defined.

autoload [ NAME ... ]
     For each of the NAMEs (which are names of functions), create a function marked undefined.  The fpath variable will be searched to find the actual function definition when the function is first referenced.

bg [ JOB ... ]
JOB ... &
     Put each specified JOB in the background, or the current job if none is specified.

bindkey -mevd
bindkey -r IN-STRING ...
bindkey [ -a ] IN-STRING [ COMMAND ] ...
bindkey -s [ -a ] IN-STRING OUT-STRING ...
     The -e and -v options put the keymaps in emacs mode and vi mode respectively; they cannot be used simultaneously.  The -d option resets all bindings to the compiled-in settings.  If not used with options -e or -v, the maps will be left in emacs mode, or in vi mode if the VISUAL or EDITOR variables contain the string vi.  Metafied characters are bound to self-insert by default.  The -m option loads the compiled-in bindings of these characters for the mode determined by the previous options, or the current mode if used alone.  Any previous binding done by the user will be preserved.  If the -r option is given, remove any binding for each IN-STRING.  If the -s option is not specified, bind each IN-STRING to a specified COMMAND.  If no COMMAND is specified, print the binding of IN-STRING if it is bound, or return a nonzero exit code if it is not bound.  If the -s option is specified, bind each IN-STRING to each specified OUT-STRING.  When IN-STRING is typed, OUT-STRING will be pushed back and treated as input to the line editor.  The process is recursive, but to avoid infinite loops the shell will report an error if more than 20 consecutive replacements happen. If the -a option is specified, bind the IN-STRINGs in the alternative keymap instead of the standard one.  The alternative keymap is used in vi command mode.

     It's possible for an IN-STRING to be bound to something and also be the beginning of a longer bound string.  In this case the shell will wait a certain time to see if more characters are typed, otherwise it will execute the shorter binding.  This timeout is defined by the KEYTIMEOUT parameter; the default is 0.4 seconds.  No timeout is done if the prefix string is not bound.

     For either IN-STRING or OUT-STRING, control characters may be specified in the form ^X, and the backslash may be used to introduce one of the following escape sequences:

     \a
          Bell character

     \n
          Linefeed (newline)

     \b
          Backspace

     \t
          Horizontal tab

     \v
          Vertical tab

     \f
          Form feed

     \r
          Carriage return

     \e
     \E
          Escape

     \NNN
          Character code in octal

     \M-XXX
          Character or escape sequence with meta bit set.  The - after the M is optional.

     \C-X
          Control character.  The - after the M is optional.

     In all other cases, \ escapes the following character.  Delete is written as ^?.  Note that \M^? and ^\M? are not the same.

     Multi-character in-strings cannot contain the null character (^@ or ^ ).  If they appear in a bindkey command, they will be silently translated to \M-^@.  This restriction does not apply to out-strings, single-character in-strings and the first character of a multi-char in-string.

break [ N ]
     Exit from an enclosing for, while, until, select, or repeat loop.  If N is specified, then break N levels instead of just one.

builtin NAME [ ARGS ] ...
     Executes the builtin NAME, with the given ARGS.

bye
     Same as exit.

cd [ ARG ]
cd OLD NEW
cd [+-]n
     Change the current directory.  In the first form, change the current directory to ARG, or to the value of HOME if ARG is not specified.  If ARG is -, change to the value of OLDPWD, the previous directory.  If a directory named ARG is not found in the current directory and ARG does not begin with a slash, search each component of the shell parameter cdpath.  If the option CDABLEVARS is set, and a parameter named ARG exists whose value begins with a slash, treat its value as the directory.

     The second form of cd substitutes the string NEW for the string OLD in the name of the current directory, and tries to change to this new directory.

     The third form of cd is equivalent to popd.

chdir
     Same as cd.

compctl [ -cfqovbCDAIFpEjBaRGuderzNOZ ] [ -k NAME ] [ -X EXPLANATION ]
[ -K FUNCTION ] [ -P PREFIX ] [ -S SUFFIX ] [ -g GLOBSTRING ]
[ -s SUBSTRING ] [ -H NUM PATTERN ] [ -l CMD ] [ ARG ... ]
compctl FLAGS + FLAGS + ...
compctl FLAGS -x PATTERN FLAGS - ... -- ARG ...
     Control the editor's completion behavior when one of ARG is the current command.  (Note that aliases are expanded before this is determined.)  With the -D flag, control default completion behavior for commands not assigned any special behavior; with -C, control completion when there is no current command.  The remaining options specify the type of command arguments to look for during completion.  If completion is attempted for a command with a pathname containing slashes and no completion is found the search is retried with the last pathname component.

     -c
          Expect command names.

     -f
          Expect filenames and filesystem paths.

     -o
          Expect option names.

     -v
          Expect variable names.

     -b
          Expect key binding names.

     -A
          Expect array names.

     -I
          Expect integer variable names.

     -F
          Expect function names.

     -p
          Expect parameter names.

     -E
          Expect environment variable names.

     -j
          Expect job names (the first word of the job leader's command line, useful with the kill builtin).

     -r
          Expect names of running jobs.

     -z
          Expect names of suspended jobs.

     -B
          Expect names of builtin commands.

     -a
          Expect alias names.

     -R
          Expect names of regular aliases.

     -G
          Expect names of global aliases.

     -u
          Expect user names.

     -d
          Expect names of disabled commands.

     -e
          Expect names of executable (and enabled) commands.

     -N
          Expect names of scalar parameters.

     -O
          Expect names of readonly variables.

     -Z
          Expect names of shell special parameters.

     -q
          If given together with a suffix (see the -S flag below) it makes this suffix be removed if the next character typed is a blank or does not insert anything (this is the same rule as used for the AUTO_REMOVE_SLASH option).

     -k NAME
          Expect names taken from the elements of $name.  Alternatively, the argument NAME itself may be a set of space- or comma-separated values in parentheses, in which any delimiter may be escaped with a backslash.  Example: compctl -k "(cputime filesize datasize stacksize coredumpsize resident descriptors)" limit.

     -K FUNCTION
          Call the given function to get the completions.  The function gets two arguments: the prefix and the suffix of the word on which completion is tried.  The function should set the variable reply to an array containing the completions (one completion per element); note that reply should not be made local.  From such a function the command line can be accessed with the -c and -l flags to the read builtin.  Example: function whoson { reply=(`users`); }; compctl -K whoson talk completes only logged-on users after talk.  Note that whoson must return an array so that just reply=`users` is incorrect.

     -X EXPLANATION
          Print the explanation string before the list of completions.  A %n in this string is replaced by the number of matches.

     -P PREFIX
          The PREFIX is inserted just before the completed string; any initial part already typed will be completed and the whole PREFIX ignored for completion purposes.  Example: compctl -j -P "%" kill.

     -S SUFFIX
          After a unique completion is found the SUFFIX is inserted after the completed string.

     -g GLOBSTRING
          The GLOBSTRING is expanded using filename globbing; it should be quoted to protect it from immediate expansion.  The resulting filenames are taken as the possible completions.  Use (/) instead of */ for directories.  The fignore special parameter is used.  More than one of these pattern may be given separated by blanks. Note that brace expansion is not part of globbing.

     -s SUBSTRING
          The SUBSTRING is split into words and these words are than expanded using all shell expansion mechanisms.  The resulting words are taken as possible completions.  The fignore special parameter is not used.  Note that -g is faster for filenames.

     -H NUM PATTERN
          The possible completions are taken from the last NUM history lines.  Only words matching PATTERN are taken.  If NUM is zero or negative the whole history is searched and if PATTERN is the empty string (or *, of course) all words are taken.

     -l CMD
          This option cannot be combined with any other option.  If it is given it restricts the range of command line words that are considered to be arguments.  By default this range contains all arguments without the command string.  If combined with extended completion and one of p[...], r[...], or R[...] the range is restricted to the arguments between the ones that are specified in the brackets.  After the range of arguments is determined completion is done in it as if they were arguments to the CMD given with this option. If this string is empty the first word in the range is taken as the command name for which to complete.  In this case, if the cursor is in the first word, command names are completed.  Example: compctl -x 'r[-exec,;]' -l  -- find completes the arguments between -exec and the following ; (or the end of the command line if there is no such string) as if they were specifying a command on their own.

     -U
          Use the whole list of possible completions, whether or not they actually match the word on the command line.  The word typed so far will be deleted.  This is most useful with a function (-K option), which can examine the word via the read builtin's -c and -l flags and use its own criterion to decide what matches.

     The second form specifies alternative options.  First completion is tried with the options before the first +.  If this produces no matches completion is tried with the flags after the + and so on. If there are no flags after the last + this means that default completion is tried if no matches were found.

     The third form specifies extended completion for the commands given as ARG.  Each PATTERN is examined in turn; when a match is found, the corresponding FLAGS, as described above for the ordinary case, are used to generate possible completions.  If no PATTERN matches, the FLAGS given before the -x are used.  Note that each pattern should be supplied as a single argument and should be quoted to prevent expansion of metacharacters by the shell.  A PATTERN is built of sub-patterns separated by commas; it matches if at least one of these sub-patterns matches (they are or'ed). These sub-patterns are in turn composed of other sub-patterns separated by white space which match if all of the sub-patterns match (they are and'ed).  An element of the sub-patterns is of the form c[...][...], where the pairs of brackets may be repeated as often as necessary, and matches if any of the sets of brackets match (an or).  These elements may be any of the following:

     s[STRING] ...
          The pattern matches if the current word on the command line starts with one of the strings given in brackets.  The STRING is not removed and is not part of the completion.

     S[STRING] ...
          Like s[STRING] but the STRING is part of the completion.

     p[FROM,TO] ...
          The pattern matches if the number of the current word is between one of the FROM and TO pairs.  The comma and TO are optional; TO defaults to the same value as FROM.  The numbers may be negative: -N refers to the N'th last word on the line.

     c[OFFSET,STRING] ...
          The pattern matches if one of the STRINGs matches the word offset by OFFSET from the current word position.

     C[OFFSET,PATTERN] ...
          Like c but uses pattern matching instead.

     w[INDEX,STRING] ...
          The pattern matches if the word in position INDEX is equal to the corresponding STRING.  Note that the word count is made after alias expansion.

     W[INDEX,PATTERN] ...
          Like w but uses pattern matching instead.

     n[INDEX,STRING] ...
          Matches if the current word contains STRING.  Anything up to the INDEX'th ocurrence of this string will not be considered part of the completion, but the rest will.

     N[INDEX,STRING] ...
          Like n[INDEX,STRING] but the string will be taken as a character class (anything up to the INDEX'th ocurrence of any of the characters in STRING will not be considered part of the completion).

     m[MIN,MAX] ...
          Matches if the total number of words lies between MIN and MAX (inclusive).

     r[STR1,STR2]...
          Matches if the cursor is after a word with prefix STR1.  If there is also a word with prefix STR2 on the command line it matches only if the cursor is before this word.

     R[STR1,STR2]...
          Like r but uses pattern matching instead.

     Example:

     compctl -u -x 's[+] c[-1,-f],s[-f+]' -g '~/Mail/*(:t)' - 's[-f],c[-1,-f]' -f -- mail

     Complete users by default.  After a -f with an optional space, complete file names; if a + follows the -f, whether or not there is a space in between, complete with the non-directory part of files in the directory ~/Mail.

continue [ NUM ]
     Resume the next iteration of the enclosing for, while, until, select, or repeat loop.  If N is specified, break out of N-1 loops and resume at the N'th enclosing loop.

declare [ ARG ... ]
     Same as typeset.

dirs [ -v ] [ ARG ... ]
     With no arguments, print the contents of the directory stack.  If the -v option is given, number the directories in the stack when printing.  Directories are added to this stack with the pushd command, and removed with the cd or popd commands.  If arguments are specified, load them onto the directory stack, replacing anything that was there, and push the current directory onto the stack.

disable [ -m ] ARG ...
     Disable the builtin ARG temporarily.  This allows you to use an external command with the same name as a shell builtin.  Without arguments all disabled builtins are printed; with the -m flag the arguments are taken as patterns (which should be quoted to preserve them from being taken as glob patterns) and all builtins matching these patterns are disabled.  Actually the same as unhash.  Builtins can be enabled with the enable command.

disown JOB ...
     Remove the specified jobs from the job table; the shell will no longer report their status, and will not complain if you try to exit an interactive shell with them running or stopped.

echo [ -n ] [ ARG ... ]
     Write each ARG on the standard output, with a space separating each one.  If the -n flag is not present, print a newline at the end.  echo recognizes the following escape sequences:

     \a
          Bell

     \b
          Backspace

     \c
          Don't print an ending newline

     \e
          Escape

     \f
          Form feed

     \n
          Newline

     \r
          Carriage return

     \t
          Horizontal tab

     \v
          Vertical tab

     \\
          Backslash

     \0NNN
          Character code in octal, with a maximum of three digits after the zero. A non-octal digit terminates the number.

     \xNN
          Character code in hexadecimal, with a maximum of two digits after the x.  A non-hexadecimal digit terminates the number.

echotc CAP [ ARG ... ]
     Output the termcap string corresponding to the capability CAP, with optional arguments.

enable [ -m ] ARG ...
     Enable the specified builtin commands, presumably disabled earlier with disable.  Without arguments the enabled builtins are printed; with the -m flag the arguments are taken as patterns (and hence should be quoted), and all builtins matching these patterns are enabled.

eval [ ARG ... ]
     Read the arguments as input to the shell and execute the resulting command(s) in the current shell process.

exit [ N ]
     Exit the shell with the exit code specified by N; if none is specified, use the exit code from the last command executed.  An EOF condition will also cause the shell to exit, unless the IGNORE_EOF option is set.

export [ NAME[=VALUE] ... ]
     The specified NAMEs are marked for automatic export to the environment of subsequently executed commands.

false
     Do nothing and return an exit code of 1.

fc [ -e ENAME ] [ -nlrdDfEm ] [ OLD=NEW ... ] [ FIRST [ LAST ]]
fc -ARWI [ FILENAME ]
     Select a range of commands from FIRST to LAST from the history list.  The arguments FIRST and LAST may be specified as a number or as a string.  A negative number is used as an offset to the current history event number.  A string specifies the most recent event beginning with the given string.  All substitutions OLD=NEW, if any, are then performed on the commands.  If the -l flag is given, the resulting commands are listed on standard output.  If the -m flag is also given the first argument is taken as a pattern (which should be quoted), and only the history events matching this pattern will be shown.  Otherwise the editor program ENAME is invoked on a file containing these history events.  If ENAME is not given, the value of the parameter FCEDIT is used.  If ENAME is -, no editor is invoked.  When editing is complete, the edited command(s) is executed.  If FIRST is not specified, it will be set to -1 (the most recent event), or to -16 if the -l flag is given.  If LAST is not specified, it will be set to FIRST, or to -1 if the -l flag is given.  The flag -r reverses the order of the commands and the flag -n suppresses command numbers when listing.  Also when listing, -d prints timestamps for each command, -f prints full time and date stamps, and -D prints elapsed times.  Adding the -E flag causes the dates to be printed in the European format (DD.MM.YYYY).

     fc -R reads the history from the given file, fc -W writes the history out to the given file, and fc -A appends the history to the given file.  fc -AI (-WI) appends (writes) only those events that are new since the last incremental append (write) to the history file.  In any case the file will have no more than SAVEHIST entries.

fg [ JOB ... ]
JOB ...
     Bring the specified JOBs to the foreground.  If no JOB is specified, use the current job.

functions [ +-tum ] [ NAME ... ]
     Equivalent to typeset -f.

getln NAME ...
     Read the top value from the buffer stack and put it in the shell parameter NAME.  Equivalent to read -zr.  The flags -c, -l, -A, -e, -E, and -n are also supported.

getopts OPTSTRING NAME [ ARG ... ]
     Checks ARG for legal options.  If ARG is omitted, use the positional parameters.  A valid option argument begins with a + or a -.  An argument not beginning with a + or a -, or the argument --, ends the options.  OPTSTRING contains the letters that getopts recognizes.  If a letter is followed by a :, that option is expected to have an argument.  The options can be separated from the argument by blanks.

     Each time it is invoked, getopts places the option letter it finds in the shell parameter NAME, prepended with a + when ARG begins with a +.  The index of the next ARG is stored in OPTIND.  The option argument, if any, is stored in OPTARG.

     A leading : in OPTSTRING causes getopts to store the letter of the invalid option in OPTARG, and to set NAME to ? for an unknown option and to : when a required option is missing.  Otherwise, getopts prints an error message.  The exit status is nonzero when there are no more options.

hash NAME PATH
     Puts NAME in the command hash table, associating it with the pathname PATH.  Whenever NAME is used as a command argument, the shell will try to execute the file given by PATH.

history [ -nrdDfEm ] [ FIRST [ LAST ]]
     Same as fc -l.

integer [ +-FBlrtux ] [ NAME[=VALUE] ]
     Same as typeset -i, except that options irrelevant to integers are not permitted.

jobs [ -lprs ] [ JOB ... ]
     Lists information about each given job, or all jobs if JOB is omitted.  The -l flag lists process ids, and the -p flag lists process groups.  If the -r flag is given only running jobs will be listed; if the -s flag is given only stopped jobs are shown.

kill [ -SIG ] JOB ...
kill -l
     Sends either SIGTERM or the specified signal to the given jobs or processes.  Signals are given by number or by names (with the prefix SIG removed).  If the signal being sent is not KILL or CONT, then the job will be sent a CONT signal if it is stopped.  The argument JOB can be the process id of a job not in the job list.  In the second form, kill -l, the signal names are listed.

let ARG ...
     Evaluate each ARG as an arithmetic expression. See Arithmetic Evaluation, for a description of arithmetic expressions.  The exit status is 0 if the value of the last expression is nonzero, and 1 otherwise.

limit [ -h ] [ RESOURCE [ LIMIT ]] ...
limit -s
     Limit the resource consumption of children of the current shell.  If LIMIT is not specified, print the current limit placed on RESOURCE; otherwise set the limit to the specified value.  If the -h flag is given, use hard limits instead of soft limits.  If no RESOURCE is given, print all limits.  See also ulimit. RESOURCE is one of:

     cputime
          Maximum CPU seconds per process.

     filesize
          Largest single file allowed.

     datasize
          Maximum data size (including stack) for each process.

     stacksize
          Maximum stack size for each process.

     coredumpsize
          Maximum size of a core dump.

     resident
     memoryuse
          Maximum resident set size.

     memorylocked
          Maximum amount of memory locked in RAM.

     descriptors
          Maximum value for a file descriptor.

     openfiles
          Maximum number of open files.

     vmemorysize
          Maximum amount of virtual memory.

     Which of these resource limits are available depends on the system. LIMIT is a number, with an optional scaling factor, as follows:

     Nh
          Hours.

     Nk
          Kilobytes.  This is the default for all but cputime.

     Nm
          Megabytes or minutes.

     MM:SS
          Minutes and seconds.

local [ +-LRZilrtu [N]] [ NAME[=VALUE] ]
     Same as typeset, except that the options -x and -f are not permitted.

log
     List all users currently logged in who are affected by the current setting of the watch parameter.

logout
     Exit the shell, if this is a login shell.

popd [ +-N ]
     Removes entries from the directory stack.  With no arguments, removes the top directory from the stack, and performs a cd to the new top directory.  With an argument of the form +N, remove the N'th entry counting from the left of the list shown by the dirs command, starting with zero, and change to that directory. With an argument of the form -N, remove the N'th entry counting from the right.  If the PUSHD_MINUS option is set, the meanings of + and - in this context are swapped.

print [ -RnrslzpNDPoOic ] [ -uN ] [ ARG ... ]
     With no flags or with flag -, the arguments are printed on the standard output as described by echo, with the following differences: the escape sequence \M-x metafies the character x (sets the highest bit), \C-x produces a control character (\C-@ and \C-? give the characters NULL and delete) and \E is a synonym for \e.  Finally, if not in an escape sequence, \ escapes the following character and is not printed.

     -R
     -r
          Ignore the escape conventions of echo.  The -R option will print all subsequent arguments and options.

     -s
          Place the results in the history list instead of on the standard output.

     -n
          Do not add a newline to the output.

     -l
          Print the arguments separated by newlines instead of spaces.

     -N
          Print the arguments separated and terminated by nulls.

     -o
          Print the arguments sorted in ascending order.

     -O
          Print the arguments sorted in descending order.

     -i
          If given together with -o or -O, makes the sort be case-insensitive.

     -c
          Print the arguments in columns.

     -uN
          Print the arguments to file descriptor N.

     -p
          Print the arguments to the input of the coprocess.

     -z
          Push the arguments onto the editing buffer stack, separated by spaces; no escape sequences are recognized.

     -D
          Treat the arguments as directory names, replacing prefixes with ~ expressions, as appropriate.

     -P
          Recognize the same escape sequences as in the PROMPT parameter.

pushd [ ARG ]
pushd OLD NEW
pushd +-N
     Change the current directory, and push the old current directory onto the directory stack.  In the first form, change the current directory to ARG.  If ARG is not specified, change to the second directory on the stack (that is, exchange the top two entries), or change to the value of HOME if the PUSHD_TO_HOME option is set or if there is only one entry on the stack.  If ARG is -, change to the value of OLDPWD, the previous directory. If a directory named ARG is not found in the current directory and ARG does not contain a slash, search each component of the shell parameter cdpath.  If the option CDABLEVARS is set, and a parameter named ARG exists whose value begins with a slash, treat its value as the directory.  If the option PUSHD_SILENT is not set, the directory stack will be printed after a pushd is performed.

     The second form of pushd substitutes the string NEW for the string OLD in the name of the current directory, and tries to change to this new directory.

     The third form of pushd is equivalent to popd.

pwd
     Equivalent to print -R $PWD.

r
     Equivalent to fc -e -.

read [ -rzpqAclneE ] [ -k [NUM] ] [ -uN ] [ NAME?PROMPT ] [ NAME ... ]
     Read one line and break it into fields using the characters in IFS as separators.  In raw mode, -r, a \ at the end of a line does not signify line continuation.  With the -q flag read only one character and set NAME to y if this character was y or Y, and to n otherwise.  If the -k flag is given read only one (or NUM) characters.  If the -z flag is given, read from the editor buffer stack.  The first field is assigned to the first NAME, the second field to the second NAME, etc, with leftover fields assigned to the last NAME. If the -e or the -E flag is given, the words read are printed after the whole line is read.  If the -e flag is given, the words are not assigned to the parameters.  If the -A flag is given, the first NAME is taken as the name of an array and all words are assigned to it.  If NAME is omitted then REPLY is used for scalars and reply for arrays.  The -c and -l flags are allowed only if called inside a function used for completion (specified with the -K flag to compctl).  If the -c flag is given, the words of the current command are read. If the -l flag is given, the whole line is assigned as a scalar. Together with the -n flag these options give the number of the word the cursor is on and the index of the character the cursor is on respectively.  If -uN is specified, then input is read from file descriptor N; if -p is specified, then input is read from the coprocess.  The exit status is 0 unless end-of-file is encountered.  If the first argument contains a ?, the remainder of this word is used as a PROMPT on standard error when the shell is interactive.  The exit status is 0 unless an end-of-file is encountered.

readonly [ NAME[=VALUE]] ...
     The given NAMES are marked readonly; these names cannot be changed by subsequent assignment.

rehash [ -f ]
     Throw out the command hash table and start over.  If the -f option is given, rescan the command path immediately, instead of rebuilding the hash table incrementally.

return [ N ]
     Causes a shell function or . script to return to the invoking script with the return status specified by N.  If N is omitted then the return status is that of the last command executed.

     If return was executed from a trap, whether set by the trap builtin or by defining a TRAPXXX function, the effect is different for zero and non-zero return status.  With zero status (or after an implicit return at the end of the trap), the shell will return to whatever it was previously processing; with a non-zero status, the shell will behave as interrupted except that the return status of the trap is retained.  Note that the signal which caused the trap is passed as the first argument, so the statement return $[128+$1] will return the same status as if the signal had not been trapped.

sched [+]HH:MM COMMAND ...
sched [ -ITEM ]
     Make an entry in the scheduled list of commands to execute.  The time may be specified in either absolute or relative time.  With no arguments, prints the list of scheduled commands.  With the argument -ITEM, removes the given item from the list.

set [ +-OPTIONS ] [ +-o OPTION NAME ] ... [ -A [NAME] ] [ ARG ] ...
     Set the options for the shell and/or set the positional parameters, or declare an array.  See Options, for the meaning of the flags.  Flags may be specified by name using the -o option.  If the -A flag is given, NAME is set to an array containing the given ARGs; if no NAME is specified, all arrays are printed. Otherwise the positional parameters are set.  If no arguments are given, then the names and values of all parameters are printed on the standard output.  If the only argument is +, the names of all parameters are printed.

setopt [ -m ] [ +-OPTIONS ] [ NAME ... ]
     Set the options for the shell.  All options specified either with flags or by name are set.  If no arguments are supplied, the names of all options currently set are printed.  In option names, case is insignificant, and all underscore characters are ignored.  If the -m flag is given the arguments are taken as patterns (which should be quoted to preserve them from being interpreted as glob patterns), and all options with matching names are set.

shift [ N ] [ NAME ... ]
     The positional parameters from $N+1 ... are renamed $1, where N is an arithmetic expression that defaults to 1. If any NAMEs are given then the arrays with these names are shifted, instead of the positional parameters.

source
     Same as ., except that the current directory is always searched and is always searched first, before directories in path.

suspend [ -f ]
     Suspend the execution of the shell (send it a SIGTSTP) until it receives a SIGCONT.  If the -f option is not given, complain if this is a login shell.

test ARG ...
[ ARG ... ]
     Like the system version of test.  Added for compatibility; use conditional expressions instead.

times
     Print the accumulated user and system times for the shell and for processes run from the shell.

trap [ ARG ] [ SIG ] ...
     ARG is a command to be read and executed when the shell receives SIG.  Each SIG can be given as a number or as the name of a signal.  If ARG is -, then all traps SIG are reset to their default values.  If ARG is the null string, then this signal is ignored by the shell and by the commands it invokes.  If SIG is ZERR then ARG will be executed after each command with a nonzero exit status.  If SIG is DEBUG then ARG will be executed after each command. If SIG is 0 or EXIT and the trap statement is executed inside the body of a function, then the command ARG is executed after the function completes.  If SIG is 0 or EXIT and the trap statement is not executed inside the body of a function, then the command ARG is executed when the shell terminates.  The trap command with no arguments prints a list of commands associated with each signal.

true
     Do nothing and return an exit code of 0.

ttyctl [ -fu ]
     The -f option freezes the tty, and -u unfreezes it.  When the tty is frozen, no changes made to the tty settings by external programs will be honored by the shell, except for changes in the size of the screen; the shell will simply reset the settings to their previous values as soon as each command exits.  Thus, stty and similar programs have no effect when the tty is frozen.  Without options it reports whether the terminal is frozen or not.

type
     Same as whence -v.

typeset [ +-LRZfilrtuxm [N]] [ NAME[=VALUE]] ...
     Set attributes and values for shell parameters.  When invoked inside a function, a new parameter is created which will be unset when the function completes.  The new parameter will not be exported unless ALL_EXPORT is set, in which case the parameter will be exported provided no parameter of that name already exists.  The following attributes are valid:

     -L
          Left justify and remove leading blanks from VALUE.  If N is nonzero, it defines the width of the field; otherwise it is determined by the width of the value of the first assignment.  When the parameter is printed, it is filled on the right with blanks or truncated if necessary to fit the field.  Leading zeros are removed if the -Z flag is also given.

     -R
          Right justify and fill with leading blanks.  If N is nonzero it defines the width of the field; otherwise it is determined by the width of the value of the first assignment.  When the parameter is printed, the field is left filled with blanks or truncated from the end.

     -Z
          Right justify and fill with leading zeros if the first non-blank character is a digit and the -L flag has not been set.  If N is nonzero it defines the width of the field; otherwise it is determined by the width of the value of the first assignment.

     -f
          The names refer to functions rather than parameters.  No assignments can be made, and the only other valid flags are -t and -u. The flag -t turns on execution tracing for this function.  The flag -u causes this function to be marked for autoloading.  The fpath parameter will be searched to find the function definition when the function is first referenced.

     -i
          Use an internal integer representation.  If N is nonzero it defines the output arithmetic base, otherwise it is determined by the first assignment.

     -l
          Convert to lower case.

     -r
          The given NAMEs are marked readonly.

     -t
          Tags the named parameters.  Tags have no special meaning to the shell.

     -u
          Convert to upper case.

     -x
          Mark for automatic export to the environment of subsequently executed commands.

     Using + rather than - causes these flags to be turned off. If no arguments are given but flags are specified, a list of named parameters which have these flags set is printed.  Using + instead of - keeps their values from being printed.  If no arguments or options are given, the names and attributes of all parameters are printed.  If just the -m flag is given the arguments are taken as patterns (which should be quoted), and all parameters or functions (with the -f flag) with matching names are printed.

ulimit [ -Hacdflmnopstv ] [ LIMIT ]
     Set or display a resource limit.  When setting a limit it will apply to the children of the shell but not to the shell itself. The value of limit can be a number in the unit specified below or the value unlimited.  If the -H flag is given use hard limits instead of soft limits.  See also limit.

     -a
          Lists all of the current resource limits.

     -c
          Maximum size of core dumps, in 512-byte blocks.

     -d
          Maximum size of the data segment, in Kbytes.

     -f
          Maximum size of individual files written, in 512-byte blocks.

     -l
          Maximum size of locked-in memory, in Kbytes.

     -m
          Maximum size of physical memory, in Kbytes.

     -n
          Maximum number of file descriptors.

     -o
          Maximum number of open files.

     -p
          Maximum number of processes.

     -s
          Maximum size of stack, in Kbytes.

     -t
          Maximum number of CPU seconds.

     -v
          Maximum size of virtual memory, in Kbytes.

umask [ MASK ]
     The umask is set to MASK.  MASK can be either an octal number or a symbolic value as described in chmod(1).  If MASK is omitted, the current value is printed.

unalias [ -m ] NAME ...
     The alias definition, if any, for each NAME is removed.  With the -m flag, the arguments are taken as patterns (which should be quoted), and all aliases with matching names are removed.

unfunction [ -m ] NAME ...
     The function definition, if any, for each NAME is removed.  With the -m flag, the arguments are taken as patterns (which should be quoted), and all function with matching names are removed.

unhash [ -m ] NAME ...
     The entry in the command hash table, if any, for each NAME is removed.  With the -m flag, the arguments are taken as patterns (which should be quoted), and all entries for commands with matching names are removed.

unlimit [ -h ] RESOURCE ...
     The resource limit for each RESOURCE is set to the hard limit.  If the -h flag is given and the shell is running as root, the hard resource limit for each RESOURCE is removed.

unset [ -m ] NAME ...
     Each named parameter is unset.  With the -m flag, the arguments are taken as patterns (which should be quoted), and all parameters with matching names are unset.

unsetopt [ -m ]  [ +-OPTIONS ] [ NAME ... ]
     Unset the options for the shell.  All options specified either with flags or by name are unset.  With the -m flag, the arguments are taken as patterns (which should be quoted), and all options with matching names are unset.

vared [ -c ] [ -p PROMPT] [ -r RPROMPT ] NAME
     The value of the parameter NAME is loaded into the edit buffer, and the line editor is invoked.  When the editor exits, NAME is set to the string value returned by the editor.  If the -c flag is given, the parameter is created if it doesn't already exist.  If the -p flag is given, PROMPT will be taken as the prompt to display at the left.  If the -r flag is given, RPROMPT will be taken as the prompt to display at the right.

wait [ JOB ... ]
     Wait for the specified jobs or processes.  If JOB is not given then all currently active child processes are waited for.  Each JOB can be either a job specification or the process-id of a job in the job table.  The exit status from this command is that of the job waited for.

whence [ -acpvm ] NAME ...
     For each name, indicate how it would be interpreted if used as a command name.  The -v flag produces a more verbose report.  The -p flag does a path search for NAME even if it is a shell function, alias, or reserved word.  The -c flag prints the results in a csh-like format.  The -a flag does a search for all occurences of NAME throughout the command path.  With the -m flag, the arguments are taken as patterns (which should be quoted), and the information is displayed for each command matching one of these patterns.

which
     Same as whence -c.

Invocation
**********

zsh [ +-OPTIONS ] [ +-o OPTION ] ...  [ -c STRING ] [ ARG ... ]

Commands are first read from /etc/zshenv.  If the -f flag is given or if the NO_RCS option is set within /etc/zshenv, all other initialization files are skipped. Otherwise, commands are read from $ZDOTDIR/.zshenv (if ZDOTDIR is unset, HOME is used instead).  If the first character of argument zero passed to the shell is -, or if the -l flag is present, then the shell is assumed to be a login shell, and commands are read from /etc/zprofile and then $ZDOTDIR/.zprofile.  Then, if the shell is interactive and the NO_RCS option is unset, commands are read from /etc/zshrc and then $ZDOTDIR/.zshrc.  Finally, if the shell is a login shell, /etc/zlogin and $ZDOTDIR/.zlogin are read.

If the -s flag is not present and an argument is given, the first argument is taken to be the pathname of a script to execute. The remaining arguments are assigned to the positional parameters.  The following flags are interpreted by the shell when invoked:

-c STRING
     Read commands from STRING.

-s
     Read command from the standard input.

-i
     If this flag is present or the shell input and output are attached to a terminal, this shell is interactive.

Wrapping Up
***********

See Also
========

sh(1), csh(1), tcsh(1), itcsh(1), rc(1), bash(1), ash(1), ksh(1), clam(1), strftime(3).

Files
=====

$ZDOTDIR/.zshenv

$ZDOTDIR/.zprofile

$ZDOTDIR/.zshrc

$ZDOTDIR/.zlogin

$ZDOTDIR/.zlogout

/tmp/zsh*

/etc/zshenv

/etc/zprofile

/etc/zshrc

/etc/zlogin

Author
======

Paul Falstad (pf@z-code.com).  Programmable completion was implemented by Sven Wischnowsky (oberon@cs.tu-berlin.de) and Peter Stephenson (pws@s-a.amtp.liv.ac.uk).

Availability
============

The latest official release of zsh is available via anonymous ftp from cs.ucsd.edu (132.239.51.3), in the directory pub/zsh.  The beta release of zsh 2.4 is available from carlo.phys.uva.nl (145.18.220.25), in the directory pub/bas/zsh.

Undocumented Features
=====================

Known only to the recipients of the zsh mailing list, zsh-list@sterling.com.  If you run into problems, please send your questions and patches to the mailing list.  To subscribe to zsh-list, send an email message with the body subscribe zsh-list to Majordomo@sterling.com.