How to increment version number in a shell script?

Question

The following simple version control script is meant to find the last version number of a given file, increment it, run a given command with the newly created file (e.g., ed

Answer 1

Here is an even shorter version that also supports a postfix (nice for -SNAPSHOT)

$ cat versions
1.2.3.44
1.2.3.9
1.2.3
9
42.2-includes-postfix

$ perl -pe 's/^((\d+\.)*)(\d+)(.*)$/$1.($3+1).$4/e' < versions
1.2.3.45
1.2.3.10
1.2.4
10
42.3-includes-postfix

Explanation

I used regex to capture 3 parts. The stuff before the last position, the number to increment, and the stuff after.

• ((\d+\.)*) - stuff of the from 1.1.1.1.1.
• (\d+) - the last digit
• (.*) - the stuff after the last digit

I then use the e option to allow expressions in the replace part. Note with the e option \1 becomes a variable $1 and you need to concatenate variables with the dot operator.

• $1 - the capture group of 1.1.1.1.1.
• ($3+1) - increment the last digit. note $2 is used in the sub group of $1 to get the repeated 1.
• $4 - the stuff after the last digit