Trimming Files
Using the head and tail commands, you can quickly trim files down. This may be useful for something like a long log file where you only care about the logs after some specific line.
Get First N Lines
head -n 3 "$file"Get Last N Lines
tail -n 3 "$file"Get All Lines After Line N
You can use tail with -n +<num> to get the last [num] lines of the file. Note that that the + is important here as it signals to tail that the number is relative to the beginning of the file and not the end.
tail -n +4 "$file"