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

Pure Bash:

increment_version ()
{
  declare -a part=( ${1//\./ } )
  declare    new
  declare -i carry=1

  for (( CNTR=${#part[@]}-1; CNTR>=0; CNTR-=1 )); do
    len=${#part[CNTR]}
    new=$((part[CNTR]+carry))
    [ ${#new} -gt $len ] && carry=1 || carry=0
    [ $CNTR -gt 0 ] && part[CNTR]=${new: -len} || part[CNTR]=${new}
  done
  new="${part[*]}"
  echo -e "${new// /.}"
} 

version='1.2.3.44'

increment_version $version

result:

1.2.3.45

The version string is split and stored in the array part. The loop goes from the last to the first part of the version. The last part will be incremented and possibly cut down to its original length. A carry is taken to the next part.