Comandos de la terminal/which

[rrc@Llawyr ~]$ which --help
Usage: which [options] [--] COMMAND [...]
Write the full path of COMMAND(s) to standard output.

  --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.

Recommended use is to write the output of (alias; declare -f) to standard
input, so that which can show aliases and shell functions. See which(1) for
examples.

If the options --read-alias and/or --read-functions are specified then the
output can be a full alias or function definition, optionally followed by
the full path of each command used inside of those.

Report bugs to <which-bugs@gnu.org>.

[rrc@Llawyr ~]$ which --version
GNU which v2.20, Copyright (C) 1999 - 2008 Carlo Wood.
GNU which comes with ABSOLUTELY NO WARRANTY;
This program is free software; your freedom to use, change
and distribute this program is protected by the GPL.

[rrc@Llawyr ~]$ which HolaMundo
which: no HolaMundo in (/usr/local/bin:/usr/bin:/usr/games:/usr/lib64/qt4/bin:/home/rrc/bin)

[rrc@Llawyr ~]$ which printf
/usr/bin/printf

[rrc@Llawyr ~]$ which fsck.ext4
which: no fsck.ext4 in (/usr/local/bin:/usr/bin:/usr/games:/usr/lib64/qt4/bin:/home/rrc/bin)

[rrc@Llawyr ~]$ su -
Password: 
[root@Llawyr ~]#  which fsck.ext4
/usr/sbin/fsck.ext4

[root@Llawyr ~]# which HolaMundo
which: no HolaMundo in (/usr/local/sbin:/usr/sbin:/usr/local/bin:/usr/bin)

[root@Llawyr bin]# cp -a /bin/yes .
[root@Llawyr bin]# ls -al yes
-rwxr-xr-x 1 root root 28992 Dec 20 19:21 yes*
[root@Llawyr bin]# which yes
/usr/local/bin/yes

[root@Llawyr bin]# which -a yes
/usr/local/bin/yes
/usr/bin/yes

[root@Llawyr bin]# rm yes
rm: remove regular file ‘yes’? y