3.4 Viewing files

By Ravindra Bagale Last updated: 25 September 2026

Command	Use
`cat file`	Print entire file
`less file`	Scroll page by page (`Space` next, `b` back, `/word` search, `q` quit)
`more file`	Older, simpler pager
`head -n 20 file`	First 20 lines
`tail -n 20 file`	Last 20 lines
`tail -f /var/log/nginx/access.log`	Follow a log live (Ctrl+C to stop)
`wc -l file`	Count lines (`-w` words, `-c` bytes)
`diff a b`	Show differences between two files

cat /etc/os-release          # which Linux distribution and version?
head -5 /etc/passwd
sudo tail -f /var/log/messages      # Amazon Linux / CentOS system log
sudo tail -f /var/log/syslog        # Ubuntu system log