which

 

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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 argu­
        ments 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 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 match­
            ing 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
        A useful way to use this utility is by adding an alias for
        which like the following:
 
             alias which=´which --tty-only --show-tilde --show-dot´
 
        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
 
        Aliases  are  also  supported, through the use of an alias
        for which itself. An example alias for which that is using
        this feature is as follows:
 
             alias which=´alias | which --tty-only --read-alias --show-tilde --show-dot´
 
        This  will  print  the output of alias for each alias that
        matches one of the given  arguments.  For  example,  using
        this alias on itself in a tcsh:
 
             $ alias which alias \| /usr/bin/which -i !\*
             $ which which
             which   (alias | /usr/bin/which -i !*)
                  /usr/bin/which
 
 
 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 <carlo@gnu.org>
 
SEE ALSO
        bash(1)
 
 
 
                                                          WHICH(1)

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