To use a file as input for program, the
< operator can be used.
xmacroplay "$DISPLAY" < input.txt
However, is there a command to specify if I don't want to use the whole file, but only take some lines as input?
xmacroplay "$DISPLAY" < input.txt --starting_line=100 --ending_line=120
(This surely won't work, just want to know if there are option like that)