6. sed

There’s a legendary saying: “There might be people who haven’t used the sed utility, but there’s no one who has used it only once.”

And honestly? That’s so true! Once you discover the power of sed (stream editor), you’ll find yourself reaching for it constantly. It’s like that Swiss Army knife of text processing - incredibly versatile and indispensable once you get the hang of it.

Whether you’re doing simple find-and-replace operations, deleting lines, inserting text, or more complex pattern matching and substitutions, sed handles it all with elegance. The learning curve might be a bit steep at first, but trust me, it’s worth every minute you spend mastering it.

The beauty of sed is that it works on streams of text, making it perfect for processing files, pipeline operations, and automating text transformations. Once you start using it in your daily workflow, you’ll wonder how you ever lived without it!

Appendix. References

• General : http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_07_01.html