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I've been seeing a lot of sed lately, and I find it to be a rather confusing command. The manpages weren't particularly helpful, but I do know that it can be used for parsing the output of other commands.

What exactly is sed and what are it's uses? I'm looking for a comprehensive answer covering what sed is, what commonly it is used for, and some basic examples/syntax.

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From Sed man page: Sed is a stream editor. A stream editor is used to perform basic text transformations on an input stream (a file or input from a pipeline). While in some ways similar to an editor which permits scripted edits (such as ed), sed works by making only one pass over the input(s), and is consequently more efficient. But it is sed's ability to filter text in a pipeline which particularly distinguishes it from other types of editors. –  saji89 May 22 '13 at 7:03
This should be a good place to start a comprehensive answer: en.wikipedia.org/wiki/Sed –  saji89 May 22 '13 at 7:12
info sed has a lot more than man sed. Then, in /usr/share/doc/sed, there's sedfaq.txt.gz. –  user25656 Nov 3 '13 at 14:00

2 Answers 2

In basic usage it is used for 'search and replace' with stings.

echo "The quick brown fox jumps over the lazy dog" | sed 's/dog/cat/'


"The quick brown fox jumps over the lazy cat"

Where it really shines is when you start using regular expressions with it.

You might like to take a look at this article about sed, its quite comprehensive.

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sed is a powerfull command that enables you make things (remove lines, string substitution, string filtering, etc).

I could give you a list of uses with args but internet is filled of that. Searching sed usage by examples bring me a lot of results, the cute one: http://www.thegeekstuff.com/2009/10/unix-sed-tutorial-advanced-sed-substitution-examples/

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