Comparing Program Versions in POSIX Shell

blog-semver

http://havoc.io/blog/post/comparing-program-versions-in-posix-shell

git-min.sh

# Check that the version of Git installed is supported
GIT_VERSION=$(git --version | cut -d ' ' -f3)
MIN_GIT_VERSION="1.7.6"
LOWEST_GIT_VERSION=$(printf "$GIT_VERSION\n$MIN_GIT_VERSION" \
                     | sort -t "." -n -k1,1 -k2,2 -k3,3 -k4,4 \
                     | head -n 1)
if [ "$LOWEST_GIT_VERSION" != "$MIN_GIT_VERSION" ]; then
  echo "error: Git version ($GIT_VERSION) too old, need $MIN_GIT_VERSION+"
  exit 1
fi

git-version-long.sh

$ git --version
git version 1.8.5.2 (Apple Git-48)

git-version-trim.sh

$ git --version | cut -d ' ' -f3
1.9.2

git-version.sh

$ git --version
git version 1.9.2

lexical-compare-fail.sh

$ test '1.9.2' \< '1.9.12'
$ echo $?
1 # Comparison was false

lexical-compare.sh

$ test '1.9.2' \< '1.9.3'
$ echo $?
0 # Comparison was true

version-sort.sh

sort -t "." -n -k1,1 -k2,2 -k3,3 -k4,4

Apparently blog-semver url changed to https://havoc.io/post/shellsemver/