Print line at number

To print a line at a given position (say, line 10) within a file, we can use this invocation of sed:

sed '10q;d' file

d means every line will be removed from the output, except for line 10, where the deletion is short-circuited by quitting q. The result is that only line 10 is printed, and the rest of the file isn't processed.

An alternative is:

sed -n '10p' file

It is somewhat more intuitive, using -n to avoid printing lines, except for line 10 which is explicitly printed. The drawback is that the entire file is processed. Keep this in mind if performance is a priority.

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