man--which

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 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 com-
           bination 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 nor-
           mal 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 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 func-
       tion (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  directo-
       ries to be different when one of them contains a path with a symbolic link.

AUTHOR
       Carlo Wood <[email protected]>

SEE ALSO
       bash(1)

                                                                      WHICH(1)
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