How to output last part of file in linux

By Weldon James On Jul 19, 2015

How to output last part of file in linux

1. tail name command in linux

tail – output the last part of files

2. tail synopsis

tail [OPTION]... [FILE]...

3. tail command frequently used options

-c, --bytes=N
      output the last N bytes
-f, --follow[={name|descriptor}]
      output appended data as the file grows; -f,
      --follow, and --follow=descriptor are
      equivalent
-n, --lines=N
      output the last N lines, instead of the last 10

4. tail examples in linux

Lets create sample file. This file will contain names of all directories in /var/. We can also number each line for better overview.

for f in $( ls /var/ ); do echo $f; done | nl > file1

tail - create sample file
By default a tail command displays last 10 lines of given file.

tail

tail command displays last 10 lines
To display just last 3 lines from this file we use -n option:

tail -n 3 file1

tail - display last 3 lines
Moreover the same output can be produced by command:

tail -3 file1

tail - display last 3 lines without -n
To use tail command on byte level we can use -c option. This option will make tail command to display last 4 bytes (4 characters) if a given file:

tail -c 4 file1

If you wonder why we can see only 3 characters, use od command to see where the 4th byte is:

tail -c 4 file1 | od -a

tail command on byte level and od
Another very useful option for tail command is -f. This option will continuously display a file as it is dynamically edited by another process. This option is very useful for watching log files.

tail -f /var/log/syslog

Source taken from http://linuxconfig.org/

linux