# for i in $(seq 1 20); do echo $i; done | head -5
1
2
3
4
5
# for i in $(seq 1 20); do echo $i; done | head -n 5
1
2
3
4
5
# for i in $(seq 1 20); do echo $i; done | head -n +5
1
2
3
4
5
# for i in $(seq 1 20); do echo $i; done | head -n -5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
# head --version
head (GNU coreutils) 8.22
Copyright (C) 2013 Free Software Foundation, Inc.
ライセンス GPLv3+: GNU GPL version 3 or later .
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

作者 David MacKenzie および Jim Meyering。