apropos — Search manual pages

Linux / Basic Linux commands / apropos.html

Finds manual pages by a keyword in their short descriptions.

Basic Information

What is this command?

apropos searches the whatis database of short descriptions and lists matching manual pages. It helps when you know the task but not the tool name.

By default it matches description text; -e enables regex and -s restricts sections. If the database is stale, refresh it with mandb.

What problems does it solve?

• When you remember the task but not the command name
• Browsing tools related to a topic such as compression or networking
• Checking which manual section a page lives in
• Finding commands provided by a newly installed package

Key features

Keyword search

Lists every manual page whose description contains the keyword.

• When to use: When the tool name is unknown
• What you get: You see candidate commands at once.
• Limitations: Short descriptions produce loosely related hits.

Exact matching

The -e option enables regular expressions.

• When to use: Reducing noise with word boundaries
• What you get: You can tune the search precisely.
• Limitations: A malformed regex returns nothing.

Section filter

-s 1 restricts results to user commands.

• When to use: Separating user commands from admin tools
• What you get: Picks the right page among same-name entries.
• Limitations: Unknown section numbers can hide useful results.

Installation and usage

Check whether it is installed

apropos --version

sudo apt install man-db # Debian/Ubuntu sudo dnf install man-db # Fedora

Real-world examples

Search by topic

Find compression-related commands.

apropos compression | head

Exact match

Narrow the match with a regex.

apropos -e '^zip'

Refresh then search

Update the database and search again.

sudo mandb
apropos 'disk usage'