How to use the command 'locate' (with examples)

The ’locate’ command is used to quickly find filenames on a system. It searches a pre-built database that contains information about all the files and directories on the system. By using patterns or exact filenames, ’locate’ can efficiently locate files.

Use case 1: Look for pattern in the database

Code:

locate "pattern"

Motivation: This use case is useful when you are looking for a file or directory with a specific pattern in its name. The ’locate’ command searches the database and returns the paths to all the files or directories that match the specified pattern.

Explanation:

• locate: The command itself.
• pattern: The pattern you want to search for in file and directory names. The pattern can contain wildcards such as ‘*’, which matches any number of characters. If the pattern does not contain any wildcards, it is treated as ‘pattern’.

Example output:

/usr/lib/python3.8/tests/test_multiprocessing.py
/usr/lib/python3.8/multiprocessing/spawn.py
...

Use case 2: Look for a file by its exact filename

Code:

locate */filename

Motivation: This use case is helpful when you want to find a file by its exact filename. The ’locate’ command searches the database and returns the paths to files that have the exact specified filename, regardless of the directory they are in.

Explanation:

• locate: The command itself.
• */: Matches any character sequence in the directory path.
• filename: The exact filename you are searching for.

Example output:

/home/user/documents/filename

Use case 3: Recompute the database

Code:

sudo /usr/libexec/locate.updatedb

Motivation: This use case is necessary when you want to find recently added files. By default, the ’locate’ command uses a pre-built database that is periodically recomputed (usually weekly or daily). However, if you want to search for files that were recently added, you need to manually update the database.

Explanation:

• sudo: Executes the command with superuser privileges to ensure proper permissions.
• /usr/libexec/locate.updatedb: The command that recomputes the database, updating it with any changes in the file system.

Example output (no output indicates successful execution):

Conclusion:

The ’locate’ command is a powerful tool for quickly finding filenames on a system. By using patterns or exact filenames, you can efficiently locate files and directories. Remember to periodically update the database using the ’locate.updatedb’ command if you want to search for recently added files.