head : output the first part of files
[SYNOPSIS] head OPTION FILE
OPTION
  display the top 10 lines without any options
-n NUM print the first NUM lines instead of the first 10
with the leading '-', print all but the last NUM lines of each file
# head -n 20 file
-c NUM print the first NUM bytes of each file
with the leading '-', print all but the last NUM bytes of each file
# head -c 10 file