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WHICH(1)                                                              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 executa-
       bles 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 combina-
           tion 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 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 successfully.

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

RETURN VALUE
       Which returns the number of failed arguments, or -1 when no `programname? 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 <carloATgnu.org>

SEE ALSO
       bash(1)



                                                                      WHICH(1)