WHICH(1)		    General Commands Manual		      WHICH(1)



NAME
       which - shows the full path of (shell) commands.

SYNOPSIS
       which [options] [--] programname [...]

DESCRIPTION
       Which takes one or more arguments. For each of its arguments it prints
       to stdout the full path of the executables that would have been exe-
       cuted when this argument had been entered at the shell prompt. It does
       this by searching for an executable or script in the directories listed
       in the environment variable PATH using the same algorithm as bash(1).

       This man page is generated from the file which.texinfo.

OPTIONS
       --all, -a
	   Print all matching executables in PATH, not just the first.

       --read-alias, -i
	   Read aliases from stdin, reporting matching ones on stdout. This is
	   useful in combination with using an alias for which itself. For
	   example
	   alias which='alias | which -i'.

       --skip-alias
	   Ignore option `--read-alias', if any. This is useful to explicity
	   search for normal binaries, while using the `--read-alias' option
	   in an alias or function for which.

       --read-functions
	   Read shell function definitions from stdin, reporting matching ones
	   on stdout. This is useful in combination with using a shell func-
	   tion for which itself.  For example:
	   which() { declare -f | which --read-functions $@ }
	   export -f which

       --skip-functions
	   Ignore option `--read-functions', if any. This is useful to explic-
	   ity search for normal binaries, while using the `--read-functions'
	   option in an alias or function for which.

       --skip-dot
	   Skip directories in PATH that start with a dot.

       --skip-tilde
	   Skip directories in PATH that start with a tilde and executables
	   which reside in the HOME directory.

       --show-dot
	   If a directory in PATH starts with a dot and a matching executable
	   was found for that path, then print "./programname" rather than the
	   full path.

       --show-tilde
	   Output a tilde when a directory matches the HOME directory. This
	   option is ignored when which is invoked as root.

       --tty-only
	   Stop processing options on the right if not on tty.

       --version,-v,-V
	   Print version information on standard output then exit success-
	   fully.

       --help
	   Print usage information on standard output then exit successfully.

RETURN VALUE
       Which returns the number of failed arguments, or -1 when no `program-
       name' was given.

EXAMPLE
       The recommended way to use this utility is by adding an alias (C shell)
       or shell function (Bourne shell) for which like the following:

       [ba]sh:

	    which ()
	    {
	      (alias; declare -f) | /usr/bin/which --tty-only --read-alias --read-functions --show-tilde --show-dot $@
	    }
	    export -f which

       [t]csh:

	    alias which 'alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'

       This will print the readable ~/ and ./ when starting  which  from  your
       prompt, while still printing the full path when used from a script:

	    > which q2
	    ~/bin/q2
	    > echo `which q2`
	    /home/carlo/bin/q2


BUGS
       The  HOME  directory  is determined by looking for the HOME environment
       variable, which aborts when this variable doesn't  exist.   Which  will
       consider	 two  equivalent  directories to be different when one of them
       contains a path with a symbolic link.

AUTHOR
       Carlo Wood <carlo@gnu.org>

SEE ALSO
       bash(1)



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