How do I extract the version number portion from the version string?

How do I extract the version number from string=customer-asset-tag-1.0.2.9?

Desired result:

Component= customer-asset-tag
version number=1.0.2.9

There are many ways of doing this, for example:

• bash and similar shells (see here for more info)

  $ string=customer-asset-tag-1.0.2.9
  $ echo -e "Component: ${string:0:18}\nVersion: ${string:19}"
  Component: customer-asset-tag
  Version: 1.0.2.9
  

• awk

  $ echo $string | awk -F- -v OFS=- '{print "Component: "$1,$2,$3; print "Version: "$4}'
  Component: customer-asset-tag
  Version: 1.0.2.9
  

  Here, we are setting awk's field delimiter to - (this is used to define fields, the 1st field is $1, the 2nd $2 etc). We are also setting the output field separator to - so it will print correctly.

• perl

  $ echo $string | perl -ne '/(.*)-([^-]+)/; print "Component: $1\nVersion: $2"'
  Component: customer-asset-tag
  Version: 1.0.2.9
  

  This is the most robust and general of the three approaches since it simply looks for the longest string of non - characters and saves that as the version and everything before the version until the last - and saves that as a component.

To extract version number

echo "customer-asset-tag-1.0.2.9"  | sed 's/[a-z-]//g'

Perl way of doing it

echo "customer-asset-tag-1.0.2.9"  | perl -ne  '/([a-z-]*)-([\d+.+]*)/; print "Component= $1\nVersion= $2\n"'

Use the following in terminal,

$ string=customer-asset-tag-1.0.2.9
$ ver=$(echo $string | awk -F- '{print $NF}')
$ Component=${string/-$ver/}
$ echo "version number=$ver"
version number=1.0.2.9
$ echo "Component=$Component"
Component=customer-asset-tag

or inside a shell script,

#!/bin/bash
string=customer-asset-tag-1.0.2.9
ver=$(echo $string | awk -F- '{print $NF}')
Component=${string/-$ver/}
echo "version number=$ver"
echo "Component=$Component"

Another awk command,

$ string=customer-asset-tag-1.0.2.9
$ echo "Component= "$(echo $string | awk '{print substr($1,1,18)}') && echo "Version number="$(echo $string | awk '{print substr($1,20)}')
Component= customer-asset-tag
Version number=1.0.2.9

Description:

• echo $string - displays the value assigned to variable string.

• echo $string | awk '{print substr($1,1,18)}'

  • | - standard output was fed as input to the following command.

  • substr($1,1,18)- From the input take the first column and display only the characters starting from the position 1 to 18 to the standard output.

• echo $string | awk '{print substr($1,20)}'

  • Display the characters starting from the 20th position in the first column from the standard input.

awk '{print substr($x,y,z)}'

x - column number
y - starting position
z - Ending position