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 executed 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 function 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
           explicity 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 executa‐
           bles which reside in the HOME directory.

       --show-dot
           If a directory in PATH starts with a dot and a matching exe‐
           cutable 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 suc‐
           cessfully.

       --help
           Print usage information on standard output then exit success‐
           fully.

RETURN VALUE
       Which returns the number of failed arguments, or -1 when no `pro‐
       gramname´ 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 follow‐
       ing:

       [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 environ‐
       ment 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)

                                                                 WHICH(1)