head / tail

head [option] [file...]
tail [option] [file...]

Option	Description
head file	Displays the first 10 lines of a file.
head -n N file	Displays the first N lines.
head -c N file	Displays the first N bytes.
head -n -N file	Displays all lines except the last N lines.
tail file	Displays the last 10 lines of a file.
tail -n N file	Displays the last N lines.
tail -c N file	Displays the last N bytes.
tail -f file	Monitors the end of a file and displays new content in real time as it is appended.
tail -F file	Same as -f, but continues tracking even if the file is deleted and recreated.
tail -n +N file	Displays lines starting from line N (skips the first N-1 lines).

The following file is used in the examples below.

~/project/data.csv

id,name,score
1,Alice,85
2,Bob,72
3,Charlie,91
4,Diana,68
5,Eve,95
6,Frank,80
7,Grace,88

Display the first 3 lines of the file.

head -n 3 data.csv
id,name,score
1,Alice,85
2,Bob,72

Display the last 3 lines of the file.

tail -n 3 data.csv
5,Eve,95
6,Frank,80
7,Grace,88

Skip the CSV header (first line) and retrieve all rows from line 2 onward.

tail -n +2 data.csv
1,Alice,85
2,Bob,72
3,Charlie,91
4,Diana,68
5,Eve,95
6,Frank,80
7,Grace,88

Check the first 3 lines of /etc/passwd.

head -n 3 /etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin

Monitor a log file in real time (press Ctrl+C to stop).

tail -f /var/log/nginx/access.log

Continue tracking a log file even after log rotation.

tail -F /var/log/app.log

Combine with a pipe to display only the latest 10 error log entries.

grep "ERROR" app.log | tail -n 10

tail -f is a command you will use almost daily for server log monitoring. To monitor multiple files at once, you can specify them together: $ tail -f file1 file2. For more powerful log monitoring, tools such as multitail and lnav are also available.

To browse an entire file interactively, use less. See also cat for displaying full file contents.