Quickest way to move a line in a text file before another line in a text file?
A scriptable editor makes this pretty straight-forward!
printf '%s\n' '55m22' 'wq' | ed -s input
This sends two commands to ed (editing the file named input):
55m22-- move line 55 after line 22wq-- save the file back to disk and quit.
A little shorter:
ex input <<<"55m22|wq"
It's somewhat longer in vi than in ed:
vi input
55Gdd23GPZZ
55G ... go to line 55
dd ... delete one line
23G ... go to line 23
P ... paste the deleted line before line 23
ZZ ... write file and exit