Linux / UNIX Shell: Sort IP Address

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Q. I’d like to sort a list of IP address stored in a text file. How do I sort by last notation or entire address under Linux or UNIX operating systems?

A.. You need to use sort command to displays the lines of its input listed in sorted order. Sorting is done based on one or more sort keys extracted from each line of input. By default, the entire input is taken as sort key. Blank space is taken used as default field separator.

Sort command to sort IP address

Here is our sample input file:

192.168.1.100
192.168.1.19
192.168.1.102
192.168.2.1
192.168.0.2

Type the following sort command:
$ sort -t . -k 3,3n -k 4,4n /path/to/file
Sample output:

192.168.0.2
192.168.1.19
192.168.1.100
192.168.1.102
192.168.2.1

Where,

  • -t . : Set field to . (dot) as our IPs separated by dot symbol
  • -n : Makes the program sort according to numerical value
  • -k opts: Sort data / fields using the given column number. For example, the option -k 2 made the program sort using the second column of data. The option -k 3,3n -k 4,4n sorts each column. First it will sort 3rd column and then 4th column.

Further readings:

  • man sort

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

11 comment

  3. You allude to sorting all columns in an IP address, but don’t specifically state how to.
    Here’s the sort command to sort all IP addresses:
    sort -t . -k 1,1n -k 2,2n -k 3,3n -k 4,4n /path/to/file

    Also, since i’m here, i wanted then to reverse my IP addresses so i could build a reverse zone file for DNS. I found an easy way:
    IP=10.120.19.18
    IP=(${IP//./ })
    Rev=${IP[3]}.${IP[2]}.${IP[1]}.${IP[0]}
    echo $Rev

    Thanks to you and your sort command for getting me started.

  5. Thanks for the great sharing… I know this is for unix/linux machine, but i would appreciate if you could share something similar (to sort ip addresses) on windows OS as well.

    Thanks

  6. I have a text file of IP addresses that I’d like to sort, which might look something like this:

    10.20.30.40 50 60.70.80.90 100
    1.2.3.4 50 5.6.7.8 80
    ab32::ff0:c23a 123 ff::ab12 80
    192.168.1.1 80 123.45.67.89 123

    I’d like to sort on the first column of IP addresses, then the third column of IP addresses. It doesn’t matter if IPv4 comes before IPv6 or vice versa.

    This sort method seems to work only for a text file containing a single column of IPv4 addresses. It’s a tough problem. This is a start for me, and I’ll have to do some trial and error and reading of “man sort.” Any tips would be appreciated.

    Thanks!

  8. Is it possible to sort by a column and then within that column? Say I had a file with a bunch of text similiar to:

    hostname1 has address 192.168.2.1
    hostname2 has address 192.168.2.23
    hostname3 has address 10.5.5.5
    hostname4 has address 192.168.3.4
    hostname5 has address 192.168.2.229

    …and so on. And I wanted to sort the file by the 4th column and then within *that* column sort the IPs numerically so that 192.68.2.23 would show up above 192.168.2.229 .. ect keeping the rest of the line intact.

    Thanks!

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