Locate

Trying to locate a file, if you're lucky you can try

# which bash
/usr/local/bin/bash

Which will search your $PATH for an executable of the same name:

Whereis locates source/binary and manuals sections for specified files, searching in a list of standard places:

# whereis bash
bash: /usr/local/bin/bash /usr/local/man/man1/bash.1.gz /usr/ports/shells/bash

Locate searches for every instance of the file in your locate database:

# locate bash
/usr/jail/usr/share/zoneinfo/Africa/Lubumbashi
/usr/local/bin/bash
/usr/local/bin/bash2
/usr/local/bin/bashbug
[snip]

Updated your locate database

On FreeBSD:

# vi /etc/locate.rc

to see you options. i.e. You might want to add /usr/ports to PRUNEPATH and then:

# /usr/libexec/locate.updatedb

You can see the database stored at /var/db/locate.database.

On Debian GNU/Linux:

--prunepath is one of the many options found in the Manual, then rebuild your database:

# /usr/bin/updatedb

You can see the database stored in /var/cache/locate/locatedb.