Aminet 1 (Walnut Creek)/Aminet - June 1993 [Walnut Creek].iso/usenet/sources/volume91/shells/cshel510/part04/csh.doc.aa

Text File | 1991-04-16 | 26KB | 701 lines

        INSTRUCTIONS FOR SHELL VERSION: 5.10  11-Apr-1991
        =================================================

  Contents
  --------

    O.    Installation
    I.    Description
    II.    Overview of Major features
    III.    Restrictions
    IV.    PIPES
    V.    Command Pre-processor
    VI.    Command Line Editing
    VII.    Function Keys
    VIII.    Shell Commands
    IX.    Special Set Variables
    X.    Functions
    XI.    Miscellaneous
    XII.    Example source files
    XIII.    Default values
    XIV.    Object oriented features
    XV.    Keymaps



O.  Installation
----------------

You  can  simply  invoke  csh  from  the  command  line or at the end of your
startup-sequence,  because  csh  is, from the AmigaDOS standpoint, not a true
shell  like  l:shell-seg.   Nevertheless,  csh is 'pure', so if your archiver
forgot to set the 'p' bit, do it right now.

Proposed final setup:  If you want to make csh resident, do the following:

Kickstart 1.3
1. Copy csh anywhere on your (hard)disk, e.g. dh1:tools
2. Make sure your s:startup-sequence contains:
    Resident CLI L:Shell-Seg SYSTEM PURE ADD
    Resident dh1:tools/csh ADD
    NewCLI FROM s:csh-startup
    EndCLI
3. Put the following in s:csh-startup
    csh -r s:firstlogin.sh
4. In s:firstlogin.sh, put any commands to be called only once, like setmap,
   assign, setclock. This is a shell script, use # for comments, and don't
   use .key type commands. At the end of this file, add
    source s:login.sh
5. In s:login.sh, you put any commands that need to be invocated on every
   invocation, like 'alias', 'set' and so on.
6. Put the following the s:cli-startup and s:shell-startup, so csh will be
   started in any window opened by NewCLI or from workbench.
    csh s:login.sh

Kickstart 2.0
1. Copy csh anywhere on your (hard)disk, e.g. dh1:tools
2. Make sure your s:startup-sequence contains:
    Resident dh1:tools/csh ADD
    csh s:firstlogin.sh
3. Proceed from step 4 in kickstart 1.3


Additionally,  I  recommend  to  assign CSH:  somewhere and put your docs and
cshell  scripts there.  You can do the assign from inside the shell, it's not
needed at startup.


I.  DESCRIPTION
---------------

This version of Shell is the successor of:
    Shell V2.04 (C)Copyright 1986, Matthew Dillon, All Rights Reserved
    Shell V2.04M-V2.07M by Steve Drew
    Shell V2.08MI, V3.xxA and V4.xxA by Carlo Borreo & Cesare Dieni
    Shell V5.xxL by Urban Mueller

If you have any wishes, bug reports or beer bottles, send them to:

       FIDONET :  AUGL BBS, 2:302/906
       INTERNET:  [e-mail]
or
       Urban Mueller
       Schulhausstrasse 83
    CH-6312 Steinhausen
       SWITZERLAND

Any sign of intelligent life welcome!

Please  check the 'restrictions' and 'known bugs' paragraphs before reporting
any  bugs.  The support BBS is AUGL, [phone], [phone], +41 75 2
15 87 (all lines USRobotics HST) login='cshell', password='support'

For  versions prior to 5.00 send suggestions/criticism/anything else to Carlo
Borreo or Cesare Dieni at:

       BITNET:  [e-mail]
       FIDONET: 2:332/602.0@FIDONET
or
       Carlo Borreo            Cesare Dieni
       Via G. Berio 34        Via G. Taddei 3
       I-18100 Imperia        I-56100 Pisa
       Italy            Italy

You may distribute this program unmodified and for non-profit only.

*** YOU MAY NOT MODIFY THIS PROGRAM AND REDISTRIBUTE IT ***

If  everyone  writes his own version of Shell and distributes it, we would be
covered  by  Shell  versions.   If  you make a modification to Shell that you
would  like  to  share  with  other users, please send us a DIFF output, or a
description of what you need.

CREDITS
-------

Arexx is a program by William Hawes.
Cygnus Ed Professional (C) 1988 CygnusSoft Software.

Many  thanks  to  all  who  gave me feedback, namely Eddy Carroll, Patrizio
Rusconi,  Allard  Siemelink,  Magnus Heldestad, Roddi Walker, Roy Haverman,
Steve Koren, Randell Jesup and all I forgot to mention.


II. OVERVIEW
------------

Shell  provides a convenient AmigaDos alternative command interface.  All its
commands  are  internal  and  thus  does not rely on the c:  commands for any
functionality.

Major features include:
    - command line editing
    - simple history
    - piping
    - aliases with arguments
    - variables & variable handling (embedded variables)
    - file name expansion via wild carding ('?', '*' and more)
    - conditionals (if/else etc..)
    - source files  (w/ gotos and labels)
    - tab file name completion
    - object oriented features (file classes, actions)
    - many built in commands to speed things up
    - full functionality on VT terminals
    - freely programmable command line editing

Shell  runs  on  minimum stack, for recursive aliases and source files better
increase stack to 8K or more.

If you use CShell for the first time, remember the following:
    - CShell internal commands must be lowercase & can be abbreviated
    - AmigaDOS command 'Execute' causes some trouble. You cannot redirect
      it, you must not rename it, and you get no return code.
      You can also use 'source' to start your scripts, but you'll have
      to rewrite them a bit. Besides the '.key'-type commands, 'source'
      is downward compatible with 'Execute'.
    - You can always get more information on a command if csh.doc is
      in the current directoy or in csh: (you will be able to modify
      this) and you enter 'man <command>'


III. RESTRICTIONS
-----------------

The  following  applies only to Kickstart 2.0, and only to V36:  The INTERNAL
commands cannot be started.  The same is true for the commands in C:  if they
were  made  resident  using  the  AmigaDOS  'Resident' command (with cshell's
'resident' they work).  Thus, you should disable the INTERNAL residents using
the -i0 startup option if you have a V36 Kickstart.

Under  1.3, you can't start AmigaDOS residents directly.  But you can use the
-r  startup  option,  which  will  copy the AmigaDOS resident list to the arp
resident  list once (and make those residents unremovable).  I'll try to find
a better solution.

The  best  choice  under  both kickstarts is to make only csh itself AmigaDOS
resident, all other commands, if any, ARP resident.  Under 1.3, you can start
the  shell  (as any other commands) from the resident list only after you did
'resident CLI l:Shell-seg' and 'newcli'.

The  c:Execute command cannot be redirected, does not return error codes, and
might cause other problems.  It will not work at all if it has been renamed.

The  VDK:  handler and Frank Seidel's BootRam-Handler have a bug with setting
file  dates,  so  when  using  the  copy command you should try the -d and -p
switches, otherwise your file date will be bad.  (This is not a shell bug)

If using with conman it you may consider starting shell with the -a switch to
turn  off shell's command line editing and use conmans instead.  You'll lose,
however, many shell features like TAB file name completion.

CB-handler  (a  tool that installs a scrollbar in the CLI window) is not 100%
compatible  with  cshell.   The log will not always represent the real screen
contents.


IV. NOTES ON PIPES
------------------

    PIPES
    PIPES  have  been implemented using temporary T:  files.  Thus, you
    should be  careful  when  specifying  a 't:*' expansion as it might
    include the temporary files. These files are deleted on completion
    of the pipe segment.

    The file names used are completely unique, even with multiple shell
    running simultaneously.

    My  favorite  new  feature is the fact that you can now redirect to
    and  from,  and pipe internal commands.  'echo charlie >ram:x', for
    instance.  Another favorite:

    echo "echo mem | csh" | csh

    No BCPL program should be output-append redirected (>>).


V.  COMMAND PRE-PROCESSOR
-------------------------

    PREPROCESSING
    Preprocessing is done on the command line before it is passed on to
    an internal or external routine:

    ^c    where c is a character is converted to that control character.
        Thus, say '^l' for control-l.

    \233    insert character code 233 octal. Do not use values between
        200o and 232o, as they have special meanings. \240 is the
        word separator.

    $name    where name is a variable name.  Variable names can consist of
        0-9, a-z, A-Z, and underscore (_).  The contents of the
        specified variable is used.  If the variable doesn't exist,
        the specifier is used.  That is, if the variable 'i' contains
        'charlie', then '$i' -> 'charlie'.  If the variable 'i' doesn't
        exist, then '$i'->'$i' .

    ;    delimits commands.   echo charlie ; echo ben.

    ' '    (a space). Spaces delimit arguments.

    "string" a quoted string. Trailing quotes are optional. For instance,
        if you want to echo five spaces and an 'a':

        echo      a       -> a
        echo "    a"      ->      a

    \c    overide the meaning of special characters.  '\^a' is a
        circumflex and an a rather than control-a.  To get a backslash,
        you must say '\\'.

        also used to overide alias searching for commands.

    >file    specify output redirection.  All output from the command is
        placed in the specified file.

    >>file    specify append redirection (Does not work with BCPL programs).

    <file    specify input redirection. The command takes input from the
        file rather than the keyboard (note: not all commands require
        input; it makes no sense to say 'echo <charlie' since
        the 'echo' command only outputs its arguments).

    |    PIPE specifier.  The output from the command on the left becomes
        the input to the command on the right.  The current SHELL
        implimentation uses temporary files to store the data.

    !!    execute the previously executed command.
    !nn    (nn is a number).  Insert the history command numbered n (see
        the HISTORY command)
    !partial search backwards through the history list for a command which
        looks the same as 'partial', and execute it.

    #    enter comment.  The rest of the line is discarded (note: \#
        will, of course, overide the comment character's special
        meaning)

    {e hi;e ho} executes two commands as one, so they can be redirected
        as one, so they can be redirected together (see ALIAS
        command). The traling curly brace is optional.

    $(foo)    insert the stdout of the command 'foo' at this position of
        the command line. Every line of the output will count as one
        argument. The closing parenthesis is optional.

    `foo`    insert the stdout of the command 'foo' at this position of
        the command line. Every blank separated word will count as
        one argument. The trailing backtick is optional.

    Please note the subtle differences between
        alias count {echo one;echo two}
        alias count "echo one;echo two
    The first form will create an alias that contains a local alias. The
    other will create a plain alias. Also, things within braces will not
    be parsed more than once, therefore a backslash needs not be pre-
    ceeded by a pair of backslashes. Thus the commands look the same as
    if they were to be typed in at the prompt. To echo lots of '#',
    either use:
        forever {echo \#
        forever "echo \\\#
    A block can spread over several line. Refer to the SOURCE command.


VI. COMMAND LINE EDITING
------------------------

    o Command line can be up to 255 chars.
    o Inserts  and  deletes  are handled correctly over multiple screen
      lines.
    o Shell  will  keep  track  of the line width should the window get
      resized.

    EDITING

    -- MOVING --
    Left Arrow      One character left
    Right Arrow      One character right
    Shift-Left Arrow  One word left
    Shift-Right Arrow One word right
    ESC-Left Arrow      Beginning of line (^A) (^Z)
    ESC-Right Arrow      End of line       (^E)
    -- DELETING --
    Backspace      Previous character
    Del          Character under cursor
    ESC-Backspace      Previous word     (^W)
    ESC-Del          Next word
    ESC-x-Backspace      To start of line  (^B)
    ESC-x-Del      To end of line    (^K)
    ESC-d          Entire line       (^X)
    -- HISTORY --
    Up Arrow      Recall previous commands
    Down Arrow      Recall commands
    Shift-Up Arow      Get history from partial (or number)
    Shift-Down Arrow  Go below last command of history
    ESC-Up Arrow      Get start of history
    ESC-Down Arrow      Get end of history
    ESC-!          Get history from partial (or number)
    ^T          Insert tail (all but first word) of previous line
    ^P          Duplicate previous word (useful for mv)
    -- COMPLETION --
    TAB          Inserts first matching file name
    Shift-TAB      Inserts longest common substring
    ESC-TAB          Inserts all matching file names
    ESC-c          Does a quick cd on left word (TAB for cycling)
    ESC-~          Inserts the last current directory
    -- EXECUTING LINE --
    Return          Executes line
    ESC-Return      Executes this line of history & brings up next one
    ^N          Next line. Don't exec this one but store history
    ^\          EOF (directly exits)
    -- MISCELLANEOUS --
    ^L          Retype current line.
    ^O          Echo a ^O
    ^R          Repeat last command (don't play with this)
    ^U          Undo/Redo last edit
    ESC-i          Toggle Insert/Overwrite
    f1-f10          Execute command if variable exists.
    F1-F10          More commands (Shifted f keys).
    Help          Invokes help command

Whenever  the cursor is placed on or directly after an incomplete file name
and   you  press  TAB,  CShell  inserts  for  the  first  filename  (sorted
alphabetically)  that  matches  the name part already typed.  Any wildcards
are allowed here, if none are given, '*' is appended.  Immediately pressing
TAB  again  brings  up  the  next  file  name  that  matched the substring.
Shift-TAB  will  only  insert  the  as  much as is common to all files that
matched  you  abbreviation.   If  pressed  again,  behaves  just  like TAB.
ESC-Tab  inserts  the  name  of the directory where you would have ended up
with a quick cd to that substring.

Note  that  ^D  now  means  'quit  batchfile' like under AmigaDOS and is no
longer used for quitting CShell. If you want it back, enter 'keymap 0 4=41'

The  CTRL  keys FGVY are unset, feel free to map them to any function (see
chapter XV).  You can also remap all preset keys.

VII. FUNCTION KEYS
------------------

    FUNKEY
    Function keys now insert text to the current position on the command
    line. They maybe terminated with a ^M (return). f1 would be non shifted
    where as F1 is shifted.
    Most of functions key have a default definition, but it may be changed.

        $ set f1 dir df0:^M

    will add the text 'dir df0:<return>' to the current line.

        $ set f1 dir

    would only add 'dir' you could then enter ' df0:<return>'


VIII. SHELL COMMANDS
--------------------

    STARTUP OPTIONS
    First to start shell from a CLI:

    shell [-abcfiknstv] [-c command;command]
    shell [-abcfiknstv] [batchfile1 ... batchfileN]

     -a  AUX: mode. No command line editing and text highlighting
     -b  starts shell in background, which means only task priority -1.
     -c  allows execution of one command line and then exits out
         of  shell.   This  is  useful for running an internal shell
         commands in the background or from an external application:
        Run csh -c "dir df0:; copy -r df0: df1: >nil:; echo Done"
     -f  starts shell in foreground, which means only task priority 1.
         you might reset this prioritiy to 0 at the end of your .login
     -i0 disables INTERNAL residents. for V36 kickstarts.
     -k  sets _nobreak before doing anything
     -n  suppresses starting of s:.login
     -r  copies the amiga resident list to the arp resident list. You
         can't remove them anymore. No copying when under kick 2.0 or
         if arp residents present.
     -s  globally enables the star '*' as alias for #? in AmigaDOS 2.0
     -t  terminal mode. You can use command line editing and text high-
         lighting on a VT100 compatible terminal.
     -v  sets _verbose to 'hs' before doing anything.

    Under 1.3, the best thing you can do is to make csh resident using
    the AmigaDOS Resident command in the startup-sequence, then start
    it with the option -r, so you can start another resident csh from
    inside csh. NOTE: Residents copied using -r cannot be removed! I
    advise you to use the internal resident command for all but csh
    itself.

    COMMAND EXECUTION

    Internal shell commands are case sensitive and may be abreviated.

   The first argument is the command-name... here is (in order) how Shell
   tries to execute it:

    1)  The alias list is searched for an alias with an exactly
        matching name.
    2)  Internal commands list is scanned for a command even partially
        matching name (so you can, for instance, say resi for resident;
        however, you should specify enough of a command to be unique).
    3)  Then, the list of functions is scanned for a command that
        matches completely. If one is found, the result of the function
        is echoed to stdout.
    4)  Now the command is assumed to be external. Arguments with spaces
        or empty strings will be surrounded by quotes.
    5)  If the file is a directory, a 'cd <file>' will be performed to
        it.
    6)  AmigaDOS and ARP resident list are scanned for it (you can use
        Shell's 'resident' command to add/remove a file in the ARP list).
    7)  If the file is in the current directory and it's executable, it
        is started.
    8)  Then it is searched in the AmigaDOS path and c: (NOTE: Path
        assigns to C: under Kickstart 2.0 don't work; use 'path')
    9)  Now, the shell path ($_path) is searched. If it's found and
        executable, it's be started. If it has the 's' bit set, it will
        be 'c:Execute'd.
    10) If there exists a file with the suffix '.sh' and the same root
        in the current directory or in the shell path, it is 'source'd.
    11) Then the variable _rxpath is examined. If there exists a file
        with the suffix '.rexx' and the same root in the current direc-
        tory or in '$_rxpath', 'RX <file>' will be performed.
    12) If all failed, an 'exec' action is sent to the file. See chapter
        XIV for more info on classes and actions.

    To enforce that the external 'dir'-command is used, enter 'Dir'. Tt
    is a good habit to uppercase the first letter of all external com-
    mands, even if this is not necessary.

    AUTOMATIC SOURCING may be accomplished by naming shell scripts with
    a  .sh  suffix.   Thus,  if you say 'stuff' and the file 'stuff.sh'
    exists in your current or anywhere in Shell search path (NOTE: won't
    be found in the AmigaDOS path), it will be SOURCED  with all arguments
    you  have given placed  in  the  $_passed variable. This is equivalent
    to typing 'source stuff.sh'

    WILD CARD EXPANSION
    Most shell commands will accept multiple arguments that can
    be as a result of wild card expansion.  Also when calling
    an external command shell will first expand any wild cards
    to separate arguments.  If you wish to have the external command
    handle it's own wild carding you will need to insert quotes
    around the special wild card characters or use an alias (see
    explanation of 'alias')

    eg.
        arc a new.arc *.txt    - shell will expand and pass to arc
        arc a new.arc "*.txt"    - let arc expand the wild cards.
        alias arc "*a Arc $a"    - now shell will never expand

    Wildcards allowed:

    ?    match any single character
    *    match any string
    .../*    recursive search down ALL sub directories from current level
    ~    exclude pattern matching specifier
    !    synonym for ~, supported for compatibility
    &    prefixed to patterns, ask confirmation for each file
    []    character class
    ~    the previous current directory (if separated)
    Note that a pattern must contain a '?' or a '*', otherwise the other
    special characters are not recognized. Furthermore, you cannot spe-
    cify a single '?' as a pattern in the first argument to a command,
    as this will be passed on to the command in order to show its usage.

    Examples:

    df0:.../*    all files in all directories on df0:
    df0:.../!*.info    full directory tree of df0: but exclude
            any ugly .info files.
    !*.o !*.c    will result in ALL files matching since what
            doesn't match the !*.o will match the !*.c
    df1:&*        all files in root of df1:, but ask
            confirmation for each
    *.[co]        all files ending in .c or .o
    ~*.[co]        all files NOT ending in .c nor in .o
    ~        the previous current directory
    ~/*.c        all .c files in the previous current directory
    ~//        the parent of the previous current directory
    .        the current directory
    ./foo.c        the same as foo.c
    ..        the parent of the current directory
    ../foo.c    the file foo.c in the parent directory

    Note that some commands prevent wild card expansion. These are:
      - dir, rpn, whereis, window
    Those commands will expand the wild cards themselves. This is why
      dir @without( *.? , *.o )
    will not work. Instead use:
      set arg @without( *.? , *.o );dir $arg

    There is one exception to the rules given above: A single '?' as
    the first argument will *not* expand in order to allow you to get
    the usage of CLI and csh commands easily.

    The   following   symbols  are  not  yet  supported  by  wild  card
    expansions, but are accepted in search -w:

    ( | )    OR matching
    #    0 or more times the pattern following

    Examples:

    "k#a"        matches ka, kaa, kaaa, etc.
    "hel(lo|p)"    matches hello or help.


LIST OF COMMANDS:
-----------------

    ABORTLINE
    Usage    : abortline
    Example    : echo a;abort;echo b
    Results    : a

    Causes the rest of the line to be aborted. Intended for use in
    conjunction with exception handling.

    ACTION
    Usage    : action [-a] actionname file [arguments]

    Sends an action to a file. See chapter XIV CLASSES
    Options:
     -a (abort) returns 0 if failed and 1 if successful. Otherwise,
                normal error codes (10 or 11) are returned

    ADDBUFFERS
    Usage    : addbuffers drive buffers [drive buffers ...]
    Example    : addbuffers df0: 24

    Just like AmigaDOS addbuffer command, causes new buffers to be
    allocated for disk I/O. Each buffer costs 512 bytes of memory,
    CHIP memory if a disk drive.

    ALIAS
    Usage    : alias [name [command string] ]
    Example    : alias vt "echo Starting VT100;run sys:tools/vt100"

    Sets a name to be a string. You can alias a single name to a set
    of commands if you enclose them in quotes as above. By simply
    typing vt, the command line above would be executed.
    Aliases may call each other, but direct recursion is prohibited,
    so the following works: alias ls "ls -s"
    To prevent alias replacement, enter: \ls

    By typing "alias name", you will get the alias for that name, while
    with "alias" you get a list of all alias.

    ARGUMENT PASSING TO AN ALIAS:

    Usage    : alias name "%var[%var...] [ command_string ]"
          alias name "*var[%var...] [ command_string ]"
    Example    : alias xx "%q%w echo hi $q, you look $w
          xx Steve great today
    Results    : hi Steve, you look great today

    The second form of the alias command allows passing of arguments
    to any position within the command string via use of a variable
    name. To pass arguments to the end of a command string this method
    is actually not necessary. These variables are local, so they don't
    destroy another variable with the same name.
    If you specify multiple arguments, every argument will be assigned
    one word, and the last argument will be assigned the rest of the
    command line.

    Using a '*' instead of the first '%' prevents wild card expansion:
        alias zoo "*a zoo $a
    To expand the wild cards after you got them, use
        exec set a $a

    IMPLICIT ALIASES:

    Usage    : {command;command}
          {%var command;command} arg arg
    Example    : {%tmp echo $tmp $tmp} hello
    Results    : hello hello

    Curly braces define a temporary aliases. They can be redirected as
    a whole, can have arguments and local variables. They count as
    one argument, even if there are blanks inside (as with quotes), and
    they may be nested. Complex alias definitions can use the braces
    instead of quotes, although this will add some calling overhead.
    The closing curly brace is optional if at the end of line.
    Example:

    alias assert {e "Are you sure? ";input -s sure

    ASCII
    Usage    : ascii
          ascii string

    If called without arguments, ascii outputs a complete ascii table.
    Given a string, shows each character in ascii. Options:
      -h shows numbers in hexadecimal
      -o shows numbers in octal

    ASET
    Usage    : aset name value
    Example    : aset INCLUDE include:

    Set a variable in a way that is compatible with ARP/old Aztec set
    command; this is completely different from ENV: Shell variable.

    ASSIGN
    Usage    : assign
          assign logical
          assign [-lnp] logical1 physical1 [logical2 physical2 ... ]

    The first form shows all assigns.
    The second form kills one assign.
    The third form assigns logical1 to physical1 and so on. Options:
     -l creates a late-binding assign under kick 2.0, normal otherwise
     -n creates a non-binding assign under kick 2.0, normal otherwise
     -p creates a path-assign under kick 2.0, cancelled otherwise
    For definition of late/nonbinding, refer to your AmigaDOS manual.

    BASENAME
    Usage    : basename var path
    Example    : basename x df0:c/Dir    # sets x to "Dir"

    Sets var specified to basename of path.

    CAT
    Usage    : cat [-n][file file....]
    Example    : cat foo.txt

    Type the specified files onto the screen.  If no file is specified,
    STDIN in used (note: ^\ is EOF).  CAT is meant to output text files
    only. Specifying -n option you will get numbered lines.

    CD
    Usage    : cd [path]
          cd -g device1 [device2 [device3 ...]]

    Change your current working directory.  You may specify '..' to go
    back one directory (this is a CD specific feature, and does not
    work with normal path specifications).

    In most cases, you'll no more have to use the CD command. Just type
    the desired directory at the prompt (very handy in conjunction with
    file name completion). Typing a ~ alone on a command line cd's
    to prevous current directory.

    There are two situations left when you still need it:

    Entering 'cd *tem' will cd to the first name matched.

    The second form generates a list (an ascii file) of all direc-
    tories on the given devices. It will be stored in the file given
    in $_qcd (default: 'csh:csh-qcd'). Note that this ascii file  will
    not be merged but overwritten. Once you have generated this file,
    you can cd to any directory on your harddisk(s) even if it's not
    in the current directory.
    If you have two directories of the same name and you use one of
    them more, move the more important one to the beginning of the
    qcd file. You might also sort the file.
    It is legal to type just an abbreviation of the directory name
    you want to cd to. No asterisk '*' necessary. If you end up in
    the wrong directory, cd to the same directory again (best done