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

On Linux, you can view log files in real time using several tools; the most common is the tail command.

1. tail Command – Monitor Logs in Real Time

The tail command is the most common way to view log files as they grow. Use the -f option to follow a file:

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

Alternatively, the tailf command has -f built‑in, so you can run:

$ sudo tailf /var/log/apache2/access.log

When logs are rotated, use -F to follow the name even if the underlying file descriptor changes: $ sudo tail -F /var/log/apache2/access.log To display only the last two lines while following, combine -n and -f:

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

2. Multitail Command – Monitor Multiple Log Files in Real Time

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

$ sudo apt install multitail   [On Debian & Ubuntu]

$ sudo yum install multitail   [On RedHat & CentOS]

$ sudo dnf install multitail   [On Fedora 22+]

Example to view two logs simultaneously:

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

3. lnav Command – Monitor Multiple Log Files in Real Time

Install lnav similarly:

$ sudo apt install lnav   [On Debian & Ubuntu]

$ sudo yum install lnav   [On RedHat & CentOS]

$ sudo dnf install lnav   [On Fedora 22+]

View two logs with lnav:

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

4. less Command – Display Real‑Time Output of Log Files

Open a log with less and press Shift+F to follow the end of the file, similar to tail -f. You can also start less with the +F option:

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