What is the command for viewing log files in Linux?

Some of the main commands for viewing log files in Linux include:

1. Tail command: used to view the end content of a file, by default it displays the last 10 lines of the log. For example, tail -n 100 filename will show the last 100 lines of the file “filename”.
2. The head command is used to view the beginning content of a file, by default it displays the first 10 lines. For example, using head -n 100 filename will show the first 100 lines of the file named filename.
3. The cat command is used to view the contents of an entire file. For example, running cat filename will display the entire contents of the file named filename.
4. less command: used for viewing file content in a paginated manner, with support for scrolling up/down, searching, and other operations. For example, using less filename will display the content of the file filename in a paginated way.
5. The grep command is used to search for a specific string or pattern in a file. For example, running grep “pattern” filename will search for the content matching “pattern” in the file named filename.
6. zcat command: used to view the contents of compressed files (such as log files compressed with gzip). For example, zcat filename.gz will display the contents of the compressed file filename.gz.
7. The journalctl command is used to view system logs and is suitable for systems that use systemd for logging. For example, journalctl will display all of the system’s log content.
8. The dmesg command is used to view kernel logs, displaying information on the kernel’s startup and runtime messages. For example, dmesg will show the contents of the kernel logs.

The above are some commonly used commands, choose the appropriate one based on specific needs to view the log files.