[root@x1-6-00-01-4a-05-e6-e4 /]# which
Usage: /usr/bin/which [options] [--] programname [...]
Options: --version, -[vV] Print version and exit successfully.
--help, Print this help and exit successfully.
--skip-dot Skip directories in PATH that start with a dot.
--skip-tilde Skip directories in PATH that start with a tilde.
--show-dot Don't expand a dot to current directory in output.
--show-tilde Output a tilde for HOME directory for non-root.
--tty-only Stop processing options on the right if not on tty.
--all, -a Print all matches in PATH, not just the first
--read-alias, -i Read list of aliases from stdin.
--skip-alias Ignore option --read-alias; don't read stdin.
--read-functions Read shell functions from stdin.
--skip-functions Ignore option --read-functions; don't read stdin.
[root@x1-6-00-01-4a-05-e6-e4 /]# which ndiswrapper /usr/sbin/ndiswrapper
/usr/bin/which: no ndiswrapper in (/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin:/home/laptop/bin)
/usr/sbin/ndiswrapper
[root@x1-6-00-01-4a-05-e6-e4 /]#