updatedb: Linux Command and Unix Command

The updatedb command is used in conjunction with locate commands, like locate, mlocate, and slocate, to generate a searchable database of the files currently on a Linux system.

This guide focuses on the mlocate package, but an alternative, if available, will work just as well.

To install updatedb on Debian, Ubuntu, and Mint:

sudo apt install mlocate

To install updatedb on Fedora:

sudo dnf install mlocate

To install updatedb on CentOS and RHEL:

sudo yum install mlocate

To install updatedb on OpenSUSE:

sudo zypper install mlocate

To install updatedb on Arch Linux and Manjaro:

sudo pacman -S mlocate

The updatedb command comes with mlocate, and you need to use it to create a database before you can search. Since updatedb logs everything on your system by default, run it with root permissions using sudo. If you only want to use it as a regular user, you can with a few options.

First, create a general system-wide database with root permissions:

sudo updatedb

It takes a few minutes to complete, depending on how many many files are on your system. From there, find a file with mlocate. For example:

mlocate gnome

Notice the amount of junk that comes up? You can, if you choose to exclude certain directories with the -e flag.

sudo updatedb -e /usr/share, /var/lib

If you want to see which files are added to the database, use the -v flag.

sudo updatedb -v

Now, to run updatedb as a regular user, use the -l flag with a value of 0 to exclude everything that your user doesn't have access to. Then, specify a local output in your home directory with the -o flag.

updatedb -l 0 -o ~/.mlocate.db

To search that user-specific database, instead of the system one, use the -d flag to specify the user one.

mlocate -d ~/.mlocate.db

These are the most common ways to work with updatedb. For a more complete breakdown, refer to the complete technical manual below.

Below is the full technical breakdown of what the updatedb command can do.

updatedb: Update the slocate database.

updatedb [-u] [-u path] [-e path1,path2,...] [-f fstype1,...] [-l [01] ] [-q] [-v,--verbose] [-V, --version] [-h, --help] pattern...  

This manual page documents slocate, a security-enhanced version of locate. updatedb is simply a link to slocate that implies the -u option. 

-u

Create a slocate database starting at the root directory. This is the default behavior when called as updatedb.

-U path

Create a slocate database starting at path path.

-e dirs

Exclude directories in the comma-separated list dirs from the slocate database.

-f fstypes

Exclude file systems in the comma-separated list dirs from the slocate database.

-l <num>

Security level. -l 0 turns security checks off, which will make searches faster. -l 1 turns security checks on. This is the default.

-q

Quiet mode; error messages are suppressed.

-v

Verbose mode; display files indexed when creating a database.

--help

Print a summary of the options to slocate and exit.

--version

Print the version number of slocate and exit.