🖥️multitail

➡️This is a command-line reference manual for commands and command combinations that you don’t use often enough to remember it. This cheatsheet explains the multitail command with important options and switches using examples.

6 minute read

▁ ▂ ▃ ▄ ꧁ 🔴☠ COMMANDLINE-KUNGFU WITH CHEATSHEETS ☠🔴꧂▅ ▃ ▂ ▁

#  ███╗   ███╗██╗   ██╗██╗  ████████╗██╗████████╗ █████╗ ██╗██╗     
#  ████╗ ████║██║   ██║██║  ╚══██╔══╝██║╚══██╔══╝██╔══██╗██║██║     
#  ██╔████╔██║██║   ██║██║     ██║   ██║   ██║   ███████║██║██║     
#  ██║╚██╔╝██║██║   ██║██║     ██║   ██║   ██║   ██╔══██║██║██║     
#  ██║ ╚═╝ ██║╚██████╔╝███████╗██║   ██║   ██║   ██║  ██║██║███████╗
#  ╚═╝     ╚═╝ ╚═════╝ ╚══════╝╚═╝   ╚═╝   ╚═╝   ╚═╝  ╚═╝╚═╝╚══════╝

# https://wiki.natenom.de/linux/verschiedenes/multitail-schemas
# /etc/multitail.conf : Ihr sind die Farbschemas gespeichert und allgemeine Parameter
# .multitailrc : Diese Datei kann man in seinem Homepfad anlegen und eigene Defaults festlegen
# https://lanbugs.de/howtos/linux-tipps-tricks/multitail-mehre-logs-live-betrachten-und-in-farbe/
# https://www.pantz.org/software/multitail/multitailconfig.html
# http://nion.modprobe.de/blog/archives/440-Using-the-ii-irc-client.html

# Mit den Tasten a und d lassen sich Dateien, Programme oder Fenster hinzufügen und entfernen, F1 oder Strg-H bringen die Onlinehilfe auf den Schirm, mit Strg-G gelangt man zurück zur normalen Ansicht. Tippt der Nutzer w, speichert das Programm ein kurzes Shell-Skript, das multitail mit allen aktuellen Einstellungen neu startet.
# By default MultiTail does the same thing as ‘tail -f‘, i.e. view files in a real time. To view/monitor two different files in one window, the basic syntax is:

## 1. How To View 2 Files in Single Window
multitail /var/log/apache2/error.log /var/log/apache2/error.log.1
 
# To scroll through the files, hit ‘b‘ and select the file you want from the list.
# Once, you select the file, it will show you last 100 lines of that selected file, to scroll through use the cursor keys. You can also use ‘gg‘/’G‘ to move to the top/bottom of the scroll window. If you want to view more lines, hit ‘q’ to exit and hit ‘m‘ to enter a new value for the number of lines to view.

## 2. How To View 2 Files in 2 Columns
# The following command will display two different files in 2 columns.
multitail -s 2 /var/log/mysqld.log /var/log/xferlog
 
## 3. How To View Multiple Files in Multiple Columns
# Display 3 files in three columns.
multitail -s 3 /var/log/mysqld.log /var/log/xferlog /var/log/yum.log
 
## 4. Merge/View Multiple Files in Multiple Columns 
# Displays 5 logfiles while merging 2 files in one column and keep 2 files in two columns with only one in the left column.
multitail -s 2 -sn 1,3  /var/log/mysqld.log -I /var/log/xferlog /var/log/monitorix /var/log/ajenti.log /var/log/yum.log
 
## 5. How to View File and Execute a Command
# Shows 1 file while ‘-l‘ option allows command to execute in a window.
multitail /var/log/iptables.log -l "ping server.nixcraft.in"
 
# 6. How to Merge/View Two Files in Different Color 
# Merge 2 logfiles in one window, but give different color to each logfile so that you can easily understand what lines are for what logfile.
multitail -ci green /var/log/yum.log -ci yellow -I /var/log/mysqld.log

# Automatically add new files to a window:
multitail -Q /var/log/myprogram/log-2014*.txt

# Merge 2 logfiles in one window:
multitail /var/log/apache2/access.log -I /var/log/apache2/error.log

# Show 3 logfiles in 2 columns:
multitail -s 2 /var/log/apache2/access.log /var/log/messages /var/log/mail.log

# Show 5 logfiles while merging 2 and put them in 2 columns with only one in the left column:
multitail -s 2 -sn 1,3  /var/log/apache2/access.log -I /var/log/apache2/error.log /var/log/messages \
                            /var/log/mail.log /var/log/syslog

# Merge the output of 2 ping commands while removing "64 bytes received from" from only 1 of them:
multitail -l "ping 192.168.0.1" -ke "64 bytes from" -L "ping 192.168.0.2"

# Show the output of a ping-command and if it displays a timeout, send a message to all users currently logged in
multitail -ex timeout "echo timeout | wall" -l "ping 192.168.0.1"

# In one window show all new TCP connections and their state changes using netstat while in the other window displaying the merged access and error logfiles of apache2
multitail -R 2 -l "netstat -t" /var/log/apache2/access.log -I /var/log/apache2/error.log

# As the previosu example but also copy the output to the file netstat.log
multitail -a netstat.log -R 2 -l "netstat -t tcp" /var/log/apache2/access.log -I /var/log/apache2/error.log

# Show 2 logfiles merged in one window but give each logfile a different color so that you can easily see what lines are for what logfile:
multitail -ci green /var/log/apache2/access.log -ci red -I /var/log/apache2/error.log

# Show 3 rssfeeds merged in one window using rsstail
multitail -cS rsstail -l "rsstail -n 1 -z -l -d -u http://setiathome.berkeley.edu/rss_main.php" \
    	-cS rsstail -L "rsstail -n 1 -z -l -d -u http://www.biglumber.com/index.rss" -cS rsstail \
    	-L "rsstail -n 1 -z -l -u http://kernel.org/kdist/rss.xml"

# Show a Squid (proxy server) logfile while converting timestamps to something readable
multitail -cv squid /var/log/squid/access.log

# Display Q-Mail logging while converting the timestamp into human readable format
multitail -cv qmailtimestr /var/log/qmail/qmail.smtpd.log

# Merge ALL apache2 logfiles (*access_log/*error_log) into one window:
multitail -cS apache2 --mergeall /var/log/apache2/*access_log --no-mergeall -cS apache2_error \
    	--mergeall /var/log/apache2/*error_log --no-mergeall

# Monitor the logfile of an other system:     For this you need to setup a couple of things. MultiTail runs on system A, the logfile on system B.
# In this example we're going to monitor the apache2 logfile. 
	# Add the following to /etc/services:
    apache2log       20000/tcp
    
	# Add this to /etc/inetd.conf:
    apache2log stream tcp nowait root /usr/local/sbin/tail_apache2_log /usr/local/sbin/tail_apache2_log

    # and create the file /usr/local/sbin/tail_apache2_log with the following content:

    #!/bin/sh
    /usr/bin/tail -f /var/log/apache2/access.log

	# make sure that you don't forget to make that script executable (chmod +x filename).
	# Then on host A start MultiTail like this:
multitail -cS apache2 -l "telnet B 20000"

	# Please note that logfiles go in plaintext across the network. You may also need to adjust the files /etc/hosts.[allow|deny] on host B to only allow host A to connect.

# Monitoring Tomcat
multitail -cS apache2 -cS log4j "${TOMCAT_HOME}/logs/catalina.out"

#First, a notification can be generated when something special is detected (via a regular expression) in a log file. In the following example, MultiTail will follow the authentication log file and generate an e-mail alert when a failed SSH login occurred:

# The following example will tag blocked packets by a pf (packet filter) firewall on OpenBSD:
multitail -ex "sshd.*Failed password for invalid user" \
                       "echo SSH breaking attempt detected | \
                       mail -s Alert [email protected]" \
                 -i /var/log/authlog"

# The fifth field (“accept” or “block”) and will be displayed in different colors when passing from one value to the other. Combined with the screen utility, a single SSH session to a server is enough to build powerful dashboards
multitail -cf 5 " " -l "tcpdump -n -e -ttt -i pflog0"

# You can also use MultiTail to view logfiles on other hosts! use authentication via keys or use "ssh-agent": then you only once have to enter your passphrase (so login once to that host manually, and then start MultiTail)
multitail -l "ssh -t username@host tail -f file"

# tail 2x logs + command
multitail messages syslog -R 2 -l "lsof -i"

Cheatsheets are an excellent complement to other information sources like Linux man-pages, Linux help, or How-To’s and tutorials, as they provide compact and easily accessible information. While man-pages and detailed tutorials often contain comprehensive explanations and extensive guides, cheatsheets summarize the most important options forthe command multitail in a clear format. This allows users to quickly access the needed information for multitail without having to sift through lengthy texts. Especially in stressful situations or for recurring tasks, cheatsheets for multitail are a valuable resource to work efficiently and purposefully.

░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░

  █║▌│║█║▌★ KALI ★ PARROT ★ DEBIAN 🔴 PENTESTING ★ HACKING ★ █║▌│║█║▌

              ██╗ ██╗ ██████╗  ██████╗ ██╗  ██╗███████╗██████╗
             ████████╗██╔══██╗██╔═══██╗╚██╗██╔╝██╔════╝██╔══██╗
             ╚██╔═██╔╝██║  ██║██║   ██║ ╚███╔╝ █████╗  ██║  ██║
             ████████╗██║  ██║██║   ██║ ██╔██╗ ██╔══╝  ██║  ██║
             ╚██╔═██╔╝██████╔╝╚██████╔╝██╔╝ ██╗███████╗██████╔╝
              ╚═╝ ╚═╝ ╚═════╝  ╚═════╝ ╚═╝  ╚═╝╚══════╝╚═════╝

               █║▌│║█║▌ WITH COMMANDLINE-KUNGFU POWER █║▌│║█║▌

░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░

Feedback

Was this page helpful?

Glad to hear it! Please tell us how we can improve.

Sorry to hear that. Please tell us how we can improve.