tail

Q: What does tail do?

Output the last N lines of a file; follow live output. tail outputs the last N lines (default 10). The -f flag follows a file as it grows — the standard way to monitor live logs. -F is more robust than -f as it handles log rotation.

Output the last N lines of a file; follow live output.

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interactive breakdown — edit the command and press Explain

What it does

tail outputs the last N lines (default 10). The -f flag follows a file as it grows — the standard way to monitor live logs. -F is more robust than -f as it handles log rotation.

Common flags

Flag	Meaning
`-n` `--lines`	Output the last N lines
`-f` `--follow`	Follow file growth in real time
`-F` `--follow-name`	Follow by filename (survives log rotation)
`-c` `--bytes`	Output the last N bytes

Examples

tail -f /var/log/nginx/error.logLive-follow nginx error log · explain & risk-check →

tail -n 100 /var/log/syslogView last 100 syslog entries · explain & risk-check →

tail -F /var/log/app.log | grep ERRORStream and filter errors in real time · explain & risk-check →

tail -n +2 data.csvSkip header row (output from line 2 onward) · explain & risk-check →

Pro tip

Use `tail -F` instead of `tail -f` in production log monitoring — it reconnects when the file is rotated, preventing silent monitoring gaps.

head journalctl less

Open the full explainer →More in Text Processing

Reference text is hand-written and may be incomplete — check man tail for your version. Test destructive commands on a non-production system first.