Advanced Linux Command Line Utilities Every Programmer Should Know

Introduction

If you've read my previous post on the most common, yet useful, Linux commands and are looking for a bit more of a challenge, keep reading.

Here are eight of the more niche (but equally useful) command-line utilities in Linux.

Commands to Know

• chmod [parameters] [mode] [filename]

  • change mode

  • modifies permissions across multiple files and directories

  • permissions:

    • r - read

    • w - write

    • x - execute

  • groups "affected":

    • u - owner

    • g - group

    • o - others

    • a - all

  • operators:

    • '+' - adds permission

    • ' - ' - removes permission

    • '=' sets permission to value

  • ex:

    • chmod u+rw,go-r [file]

    • adds read and write permission to owner

    • removes read permission from group and others

• ln [parameters] [original filename] [link name]

  • link

  • can be either soft or hard links
    

• Hard Links
  

  • ln [original filename] [link name]

  • points to the physical data stored in the original file

  • useful for creating multiple access points to data without replicating that data (e.g. backing up data)

  • if original file is deleted or renamed, link still points to data

• Soft Links

• ln -s [original filename] [link name]

• points to the original file itself

• useful for creating shortcuts between files / directories

• if original file is deleted or renamed, link points to nothing ("dangling link")

• touch [parameters] [filename]

  • creates an empty file(s) of specified extension type

  • ex:

    • touch filename.txt

    • touch filename1.txt filename2.c filename3.py

  • similar to 'code' command exclusive to VSCode
    

Final Thoughts

Hopefully by the end of this article at least one of these commands has made its way into your software toolbelt. Thanks for reading!