How do I limit (or truncate) text file by number of lines?

How do I limit (or truncate) text file by number of lines?

shell unix sed text-files head

unix

Efficient way to get n middle lines from a very big file

unix head tail

unix

select the second line to last line of a file

linux unix head tail

unix

Unix head/tail a percentage of lines to an output file

unix lines percentage head tail

unix

Piping Perl script output to head -n 10 kills script after printing 10 lines

linux perl unix head

unix