home | help 
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 search-
     ing  for  an executable or script in the directories listed in the environ-
     ment 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 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  vari-
     able,  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)
home | help