Automatically Tag Commits on Git Push with a Shell Script

Git pre‑push hook for automatic version tagging

The script determines the most recent tag, falls back to v1.0.0 if none exists, parses the major, minor and patch components, increments the appropriate component (rolling over at 100), assembles a new tag, and creates an annotated tag.

#!/bin/sh
git pull
# Get the most recent tag; fall back to v1.0.0 if none exists
tag=$(git describe --tags `git rev-list --tags --max-count=1`)
if [ $? -ne 0 ]; then
    tag='v1.0.0'
fi

echo "current tag is $tag"

# Split the tag into major, minor, and patch components
lastTag=${tag##*.}
echo "last tag is $lastTag"

tempTag=${tag#*.}
midTag=${tempTag%.*}
echo "middle tag is $midTag"

tempTag=${tag:1}
higTag=${tempTag%%.*}
echo "high tag is $higTag"

# Increment the appropriate component, rolling over at 100
i=$(( $lastTag + 1 ))
if [ $i -gt 100 ]; then
    lastTag=0
    i=$(( $midTag + 1 ))
    if [ $i -gt 100 ]; then
        midTag=0
        let "higTag+=1"
    else
        let "midTag+=1"
    fi
else
    let "lastTag+=1"
fi

# Assemble the new tag and create it
newTag=${tag:0:1}${higTag}.${midTag}.${lastTag}
echo $newTag
git tag -a $newTag -m "new tag $newTag"

Place the script in .git/hooks and rename pre-push.sample to pre-push. Ensure the file is executable.

When a push is performed, Git runs the pre‑push hook, generates the next tag, and creates the annotated tag locally. To push the new tag to the remote, the client must have the “push tags” option enabled.