Linux / Unix: Add Line Numbers To Files

I know how to display line numbers using vim text editor. How do display line numbers in the left side for any text file under Unix or Linux operating systems?

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You can use any one of the following commands to display line numbers:

Tutorial details
DifficultyEasy (rss)
Root privilegesNo
Requirementsnl/cat/perl/awk
TimeN/A
[a] cat command

[b] nl command – Display each FILE to standard output (screen), with line numbers added.

[c] Gnu less command – Less is a program similar to more , but which allows backward movement in the file as well as forward movement

[d] awk command

[e] perl or python

Examples

The cat command syntax is:

cat -n file
cat -n /etc/hosts

The nl command syntax is:

nl file
nl /etc/hosts

Sample outputs:

     1	127.0.0.1 localhost
     2	#127.0.1.1 wks01.WAG160N wks01.nixcraft.net.in
     3	192.168.1.5	wks01
     4	# The following lines are desirable for IPv6 capable hosts
     5	::1 ip6-localhost ip6-loopback
     6	fe00::0 ip6-localnet
     7	ff00::0 ip6-mcastprefix
     8	ff02::1 ip6-allnodes
     9	ff02::2 ip6-allrouters
    10	10.10.29.72 v.b1 homerouter
    11	10.10.29.70 v.b2
    12	10.10.29.68 v.txvip1

The less command syntax is:

less -N file
less -N /etc/hosts

The awk command syntax is:

awk '{ print FNR " " $0 }' file
awk '{ print FNR " " $0 }' /etc/hosts
awk '{ print FNR "\t" $0 }' /etc/hosts

The perl syntax is:

perl -pe '$_ = "$. $_"' file
perl -pe '$_ = "$. $_"' /etc/hosts
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2 comments… add one
  • Lavi Mar 21, 2013 @ 12:23

    Another option with in a file is using vi (or vim).
    By: set number

    Very useful when editing specific lines number.
    To cancel: set nonumber

  • greatvedas Dec 16, 2015 @ 4:13

    Hello Vivek!

    The below FNR didnt work in my environment. I am using Solaris 10.
    awk '{ print FNR " " $0 }' file

    But NR worked !
    awk '{print NR," " $0}' file

    Can you confirm if FNR is working?

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