How to search Linux commands by purpose and risk level and use them safely

When this guide is useful

This is for users who want to find a list of Linux commands, how to use basic commands, file searches, log checks, port investigations, permission changes, compression, and process management examples.

• Check logs, processes, ports, and disk usage during fault investigation
• Compare file search, string search, compression/decompression commands
• Separate operations that require administrator privileges from operations that can be confirmed by general users.
• Review commands with dangerous options before executing them

Things to check before executing the command

• Additional information for this feature.
• Relative paths, wildcards, actual target after variable expansion
• Privileges and scope of influence that change between general users and root
• Can deletion, overwriting, file system operations, and process termination be undone?

Additional information for this feature.

1. Enter your purpose in the search field, such as "file search", "port", "disk space", etc.
2. Narrow down candidates by category, risk level, required authority, command type, and usage environment.
3. Open details to see syntax, main options, examples, and related commands.
4. Double-check the implementation and options in use with the man command and official documentation.
5. Experiment with safe commands that display what you're looking for, and do only what you need.

Notes on not pasting the execution example as is

The examples listed are examples to help you understand the syntax. Please change the file path, device name, PID, network interface, and user name to match your environment, and check the results of expanding quotes and wildcards.

rm, dd, mkfs, fsck, kill, changing privileges, etc. can lead to data loss or suspension if targeted incorrectly. Review the backup and recovery procedures and do not run the example exactly in a production environment.

Specific example: Safely examine files that are taking up space

If the disk usage is high, instead of deleting it immediately, narrow down the scope by checking the usage of the entire file system with df and the usage of each directory with du.

Even if the log file is large, deleting files that are open by running processes may not free up space. Also check the usage status with lsof etc.

1. Search for "disk space" and check df and du details.
2. Identify heavily used file systems with df -h.
3. Use du under the target to gradually narrow down directories with large capacity.
4. Determine whether to delete or save the file after checking its usage, retention period, and process usage.

Please do not perform a heavy search on the entire root directory at once, but limit the load by narrowing down the target file system and directory.

Frequently asked questions

Do the posted commands work the same on all Linux?

No. Please also check the man page for your usage environment, as options vary depending on GNU/BSD implementation, distribution, package, and version.

Will any commands be executed from this page?

Not executed. Search, filter, copy, and save as favorites all within your browser.