Locate a program file (UNIX)
Syntax:
which [-afLls] program...
Runs on:
QNX Neutrino, Microsoft Windows
Options:
- -a
- Find all occurrences of program in PATH.
- -f
- Display the full pathname.
- -L
- Display the long format (as in
ls -l) for each
program found, displaying link information if the file is a symlink.
- -l
- (“el”) Display the long format (as in
ls -l)
for each program found.
- -s
- Search for shared objects in the directories identified by the
LD_LIBRARY_PATH environment variable and the
_CS_LIBPATH configuration string.
Description:
The which utility searches for the specified programs.
By default, which searches the directories listed by your
PATH environment variable, but if you specify the -s
option, it searches the directories specified by
LD_LIBRARY_PATH and _CS_LIBPATH.
The Korn shell has a builtin
whence
command that's similar to the which utility but also tells you if the given command
is a reserved word, alias, builtin command, and so on.
For more information, see the entry for ksh.
Note:
QNX Neutrino also supports a toybox version of this utility.
For more information, go to the
toybox entry of this reference.
Examples:
Display the full pathname and long status for all versions of the
ls
utility found in PATH:
which -alf ls
Display the pathname for the which utility:
which which
Environment variables:
- PATH
- A colon-separated list of directories to search for executables.
- LD_LIBRARY_PATH
- A colon-separated list of directories to search for shared libraries.
Exit status:
- 0
- All input files were found.
- >0
- An error occurred.