FishMarket 1.0/FishMarket v1.0.iso/fishies/001-025/disk_024/csh/docs

Text File | 1992-05-06 | 8.7 KB | 338 lines

DOCUMENTSATION TO Za SHELL

written by Matt Dillon, Public Domain

[e-mail],  ...!ucb-vax!dillon or ...!ucbvax!dillon

    SECTION        TITLE

       0        compiling
       I        startup, auto sourcing your .login on startup
       II        simple commands
       III        Substitution/history Command line features
       IV        The alias command
       V        The set command
       VI        special set variables
       VII        labels and loops

    Appendix I    Complete Command list

0.    compiling        ------------------------------------------

    Compile each module as follows: (specifying wherever your include
    directory is with the -i on lc1)

    lc1 -idf0:include/ xxx
    lc2 -s -v xxx

    Then link with: (change libs to wherever yours are)

    alink df0:clib/lstartup.obj+main.o+globals.o+execom.o+comm1.o+comm2.o+set.o+sub.o library df0:clib/lc.lib+df0:clib/amiga.lib to shell




I.    Startup          ------------------------------------------

    Assuming you've named your executable 'shell', you may execute the
     shell FROM A CLI by typeing:

    shell

    To have the shell automagically source an initialization file,
     specify the file as an argument:

    shell .login

    You can place this line in your startup-sequence file to have
     the workbench diskette go into a shell rather than the workbench.
     It is suggested that you have a stack of 8192 (or more).  Thus, the
     entire boot from a startup-sequence file would look like:

    stack 8192
    shell .login

    Your initialization file is simply a sequence of shell commands. I
     have included my .login file as an example (see LOGIN).  The file
     usually consists of aliases.



I.    Simple Commands     ------------------------------------------

    quit            -quit out of shell
    set     varname string    -set variable to string
    unset     varname        -unset a variable
    alias     name string    -alias something to a sequence of commands
    unalias name        -unalias that something
    echo    string        -echo a string
    source    file        -source a file (execute shell coms)
    mv    from to        -exactly RENAME
    cd    dir        -change dir (you can use .. to go back one)
    rm    file file..    -remove files
    mkdir    dir dir..    -create directories
    history            -display history
    mem            -display free memory
    cat    file        -'type' a file
    dir    [file]        -directory of current dir or specified file/dir
    devinfo    [dev:]        -device information current/specified
    foreach var ( arglist) command
                -see description below
    return            -abort a source file from the source file
    if arg <=> arg        -conditional
    else            -if-else
    endif            -end of if or if-else
    label name        -create a label (only within source files)
    goto name        -goto a label   (only within source files)
    inc var [count]        -increment an numeric-ascii variable
    dec var [count]        -decrement
    input var        -input a line to the variable
    version            -print shell version #

    Any other string is taken to be a disk command an Execute() 'd.  Note
that the above commands can be abbreviated by any number of characters, so
for instance you cannot have 'a' execute 'a'.. it will execute 'alias'. You
would have to 'ram:a' (or whatever) to execute it.



III.    Substitution/history Command line features -----------------------

    * Standard commands may be abbreviated to any number of characters.
    It is suggested that you do NOT abbreviate commands in source files
    to keep those files compatible with future versions of my shell

    * Standard I/O redirection is to the current window. You may specify
    redirection (<file >file) at any place on the command line.  I/O
    redirection ONLY WORKS FOR DISK COMMANDS!  You cannot redirect
    internal commands.

    A command line looks like:

    COMMAND arg arg .... ; COMMAND arg arg ... .....

    Multiple commands are separated by a semicolon.  Alias substitution
    is checked only on the COMAND (the name of the command) argument.
    You may substitute set variables with:

    $variable_name

    You may do file expansion by specifying an argument which contains
    '?' or '*' in it.  For instance:

    echo *.c *.h

    You may do history substitution with '!': (you can get your history
    with the HISTORY command)

    !!                -re-execute last command
    !partial            -re-execute last command beginning
                     with 'partial'.
    !123                -re-execute command # 123

    For example:

    % echo charlie
    charlie
    % set a xxx
    % !e
    charlie

    You may overide any special character with the '\' character, So
    if you do not want '*' to attempt a file-name expansion, use \*.


IV.    The alias command    ------------------------------------------

    alias                -show current aliases
    alias name            -show one alias
    alias name comands        -create an alias

    % alias logout quit
    % alias hello  "echo hello; echo hello"

    The quotes are required or the semi-colon might be construed as a
    command delimeter rather than part of the alias.  There is one other
    feature of the alias. You can collect argument given after an
    alias with:

    alias name "%var commands. .. $var ... ."

    E.g. place a '%var' as the first argument in the substitution string,
    and the remaining argument will be placed in that variable for the
    duration of the alias.  For example:

    % alias xxx "%i echo $i $i $i $i"
    % xxx hello

    hello hello hello hello



V.    The set command        ------------------------------------------

    set                -show set variables
    set var                -show a single set variable or
                     set to "" if it doesn't existd
    set var name            -set a variable to a string

    .. $var..            -use a set variable



VI.    Special set variables    ------------------------------------------

    Additionaly, the following set variables are special:

    _prompt      command
    _history  value


    The _prompt variable contains the command to execute to display your
    prompt.  Usually, this is

    echo -n "%"

    The _history variable sets the number of previous commands which
    you want the shell to remember.... usually around 20


VII.    Labels and loops    ------------------------------------------

    label name
    goto label
    if arg <=> arg
    else
    endif

    label and goto can only be executed from a shell script.  These
    allow you to randomly go anywhere within a shell script.  Coupled
    with the conditionals, you can create loops if you wish.  As far
    as the conditionals go, if the left argument is numeric, both
    arguments are treated as numeric rather than string for the
    comparision.

    if 1 < 5    smaller
    if 1 > 4    larger
    if a <= back    smaller or equal
         >=        larger or equal
         =        equal
         !=        not equal

    IF's, ELSEs, and ENDIF's may be executed at any time.  Additionaly,
    a GOTO or RETURN from within a source file 'does the right thing'
    in terms of restoring the correct conditional state.


AP I    Complete Command list    ------------------------------------------

QUIT
    Quit out of the shell...

SET
SET name
SET name string
    Display set variables, display a single variable or set to "" if
    it doesn't exist, and set a variable to a string.

UNSET name name...
    unset one or more variables

ALIAS
ALIAS name
ALIAS name command
ALIAS name "command;command..."
    same as set (but in a different name space) in terms of operation.
    alias a name to a command (sequence).  When using the alias, you cannot
    abbreviate the name.

UNALIAS name name name...
    unalias one or more variables

ECHO [-n] string
    echo a string (-n means without newline at end)

SOURCE file
    execute shell commands from a file.

RETURN
    return from within a source file

MV from to
    RENAME, exactly

CD [dir]
    cd to a directory, cd to your current device base if you do not
    specify any arguments.  You may specify '..' in your path to go
    back a directory.

RM file file file...
    remove file(s)

MKDIR name name name
    create directory(s)

HISTORY
    Display history of commands that have been executed

MEM
    Display memory free

CAT file file ..
    TYPE files out

DIR [file file..]
    Directory (use current dir if no args given)

DEVINFO [dev: dev: ...]
    Device information (use current device if no args given)

FOREACH var ( arglist ) command
FOREACH var ( arglist ) "command;command..."
    Foreach space delimited item in arglist, place that item in the
specified set variable, and execute the specified command.  This allows you
to do a given operation on several 'arguments' automatically.  you MUST BE
SURE to delimit the parenthesis by a space on either side!!!

    % foreach i ( *.c ) echo $i
    comm1.c
    comm2.c
    execom.c
    globals.c
    main.c
    set.c
    sub.c

IF arg <=> arg
ELSE
ENDIF
    Conditional.  (<,>,<=,>=,=,!=)  If the left argument is a number,
both arguments are taken to be numbers and compared as numbers instead of
strings.  ALWAYS REMEMBER to put an 'endif' to end the conditional.

LABEL name
GOTO name
    Labels and goto's.  These only work inside source files, since I
use fseek() and you can't fseek() your tty.

INC var [count]
DEC var [count]
    Increment and decrement a variable numerically by one (or count if
specified)


INPUT var
    This is a cluge. You can input a string into a variable.  E.G.

    echo -n Input a filename:
    input charlie
    source $charlie

VERSION
    print the current version