Tribblix: manual page: which.1

WHICH(1) User Commands WHICH(1)

NAME

which - locate a program file in the user's path

SYNOPSIS

which [-as] command ...

DESCRIPTION

The which utility takes a list of command names and searches the path
for each executable file that would be run had these commands actually
been invoked.

Some shells may provide a built-in which command which is similar or
identical to this utility.

OPTIONS

The following options are available:

-a List all instances of executables found (instead of just
the first one of each).

-s No output, just return 0 if all of the executables are
found, or 1 if some were not found.

OPERANDS

The following operands are supported:

command The name of a command to be located.

ENVIRONMENT

See environ(7) for descriptions of the following environment variables
that affect the execution of which: PATH.

EXIT STATUS

The following exit values are returned:

0 All of the provided operands were found in the path and would
be executed if the commands were invoked.

1 One or more of the provided operands was not found in the path
or would not be executed if the commands were invoked, or an
error occurred.

2 Invalid command line options were specified.

EXAMPLES

Example 1 Locate the `ls' and `cp' commands.

$ /usr/bin/which ls cp
/usr/bin/ls
/usr/bin/cp

Example 2 Use a specific PATH and show all occurrences.

$ PATH=/usr/bin:/usr/has/bin /usr/bin/which -a edit
/usr/bin/edit
/usr/has/bin/edit

Example 3 Executable reported multiple times.

If PATH contains repeated components, the same executable can be
reported more than once:

$ PATH=/usr/bin:/usr/bin /usr/bin/which -a ls
/usr/bin/ls
/usr/bin/ls

Example 4 Do not show output.

Just exit with an appropriate return code:

$ /usr/bin/which -s ls cp
$ echo $?
0
$ /usr/bin/which -s fakecommand
$ echo $?
1

INTERFACE STABILITY

The command line interface of which is Committed. The output of which
is Committed.