Master Real-Time Log Monitoring on Linux with Tail, Multitail, Lnav & Less

Real‑time Log Viewing on Linux

Linux provides several utilities to display log file contents as they grow, with tail being the most common.

1. tail Command – Monitor Logs in Real Time

The basic -f option follows a file: $ sudo tail -f /var/log/apache2/access.log Alternatively, the tailf command has -f built‑in, so you can simply run: $ sudo tailf /var/log/apache2/access.log For rotating logs, use -F to follow a file by name even after it is recreated: $ sudo tail -F /var/log/apache2/access.log If you only need the last two lines in real‑time, combine -n and -f:

$ sudo tail -n2 -f /var/log/apache2/access.log

2. Multitail Command – Monitor Multiple Log Files

Install Multitail on Debian/Ubuntu, RedHat/CentOS, or Fedora:

$ sudo apt install multitail   [On Debian & Ubuntu]</code>
<code>$ sudo yum install multitail   [On RedHat & CentOS]</code>
<code>$ sudo dnf install multitail   [On Fedora 22+]

Display two logs side by side:

$ sudo multitail /var/log/apache2/access.log /var/log/apache2/error.log

3. lnav Command – Monitor Multiple Log Files

Install Lnav similarly:

$ sudo apt install lnav   [On Debian & Ubuntu]</code>
<code>$ sudo yum install lnav   [On RedHat & CentOS]</code>
<code>$ sudo dnf install lnav   [On Fedora 22+]

View two logs together:

$ sudo lnav /var/log/apache2/access.log /var/log/apache2/error.log

4. less Command – Real‑time Output with Shift+F

Open a log with less and press Shift+F (or start with +F) to follow the file:

sudo less +F /var/log/apache2/access.log

Further Reading

Manage Files Effectively using head, tail and cat Commands in Linux

How to Setup and Manage Log Rotation Using Logrotate in Linux

Petiti – An Open Source Log Analysis Tool for Linux SysAdmins

How to Query Audit Logs Using ‘ausearch’ Tool on CentOS/RHEL

Manage Log Messages Under Systemd Using Journalctl (Comprehensive Guide)