Using apropos in Linux

The apropos command is a Linux utility that is used to search for information about a specific topic in the manual pages on a Linux system. It is a useful tool for finding documentation and information about commands and other topics in the Linux environment.

Using apropos in Linux

To use the apropos command, you simply need to specify the topic that you want to search for. The basic syntax for the apropos command is as follows:

apropos topic

The topic argument is the keyword or phrase that you want to search for. For example, to search for information about the ls command, you could use the following apropos command:

apropos ls

This will search the manual pages on your system for any information related to the ls command, and it will print a list of all the manual pages that contain information about the ls command.

Each entry in the list will include the name of the manual page, a brief description of the page, and the section of the manual where the page is located.

To narrow the search results, you can use the -s option followed by a section number to search only a specific section of the manual.

Examples of apropos in Linux

Here are five  examples of using the apropos command to search for information in the manual pages on a Linux system:

Search section 1 of the manual for information about the ls command:

apropos -s 1 ls

Search the entire manual for information about the grep command:

apropos grep

Search the entire manual for information about regular expressions:

apropos -w regular expression

Search section 2 of the manual for information about system calls:

apropos -s 2 system call

Search the entire manual for information about the ssh command and its options:

apropos ssh

Search section 4 of the manual for information about network interfaces:

apropos -s 4 network interface

Search section 5 of the manual for information about file formats:

apropos -s 5 file format

These examples should give you a better idea of the different ways that you can use the apropos command to search for information in the manual pages on a Linux system.