utilities for comparing version strings on OS X

vcmp.sh

#!/bin/bash

# accepts as many version strings as you like
# returns them in order, one per line, highest first
function vseq()
{
  # collect arbitrary number of args
  while [ -n "$1" ]; do
    args="$args$1,"
    shift
  done
  echo $args | tr ',' '\n' | sort -t. -k1,1nr -k2,2nr -k3,3nr
}

# first argument is test value
# second argument is minimum version required
# eg vreq `ruby -v` 1.9
function vreq() 
{
  max=`vseq $1 $2 | head -1`
  if [[ $1 == $max ]]; then
    echo true; return
  fi
}

### using the functions

if [[ `vreq 1.2 1.2` ]]; then
  echo "1.2 is good"
fi

if [[ ! `vreq 1.2.1 1.20` ]]; then
  echo "1.2.1 is too low"
fi

if [[ `vreq 0.90.a 0.9.5` ]]; then
  echo '0.90.a is sufficient'
fi

echo "let's order some versions..."
vseq 1.2.100.4 1.2.3.4 10.1.2.3 9.1.2.3
# 10.1.2.3
# 9.1.2.3
# 1.2.100.4
# 1.2.3.4