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Functions

To print a specific line from a file

Terminal - To print a specific line from a file
sed -n 5p <file>
2009-10-15 11:00:48
User: Waldirio
Functions: sed
37
To print a specific line from a file

You can get one specific line during any procedure. Very interesting to be used when you know what line you want.

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
sed -n '10,20p' <filename>
2009-02-08 22:34:04
User: ergut
Functions: sed
52

Similarly, if you want to print from 10 to the end of line you can use: sed -n '10,$p' filename

This is especially useful if you are dealing with a large file. Sometimes you just want to extract a sample without opening the entire file.

Credit goes to wbx & robert at the comments section of http://www.commandlinefu.com/commands/view/348/get-line1000-from-text.#comment

awk 'NR >= 3 && NR <= 6' /path/to/file
2011-12-14 14:28:56
User: atoponce
Functions: awk
Tags: awk
6

This command uses awk(1) to print all lines between two known line numbers in a file. Useful for seeing output in a log file, where the line numbers are known. The above command will print all lines between, and including, lines 3 and 6.

sed -n '3,6p' /path/to/file
2011-12-14 15:09:38
User: flatcap
Functions: sed
Tags: sed
6

Print all lines between two line numbers

This command uses sed(1) to print all lines between two known line numbers in a file. Useful for seeing output in a log file, where the line numbers are known. The above command will print all lines between, and including, lines 3 and 6.

sed '10,20!d'
2011-03-31 15:30:24
User: tr00st
Functions: sed
3

Subtly different to the -n+p method... and probably wrong in so many ways....... But it's shorter. Just.

awk 'FNR==5' <file>
2009-10-20 22:52:41
User: dennisw
Functions: awk
1

Just one character longer than the sed version ('FNR==5' versus -n 5p). On my system, without using "exit" or "q", the awk version is over four times faster on a ~900K file using the following timing comparison:

testfile="testfile"; for cmd in "awk 'FNR==20'" "sed -n '20p'"; do echo; echo $cmd; eval "$cmd $testfile"; for i in {1..3}; do time for j in {1..100}; do eval "$cmd $testfile" >/dev/null; done; done; done

Adding "exit" or "q" made the difference between awk and sed negligible and produced a four-fold improvement over the awk timing without the "exit".

For long files, an exit can speed things up:

awk 'FNR==5{print;exit}' <file>

Know a better way?

If you can do better, submit your command here.

What others think

It might be better to have

sed -n '5{p;q}' file

so you do not read the rest of a possibly long file.

Comment by arcege 248 weeks and 6 days ago

I suggest following -

awk 'NR == 3'

This will also do the same job :-). But its shorter...

Comment by rajarshi 211 weeks and 1 day ago

Your point of view

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