Git commit-msg hook which adds github issue number to commit message baed on current branch name.

commit-msg

#!/bin/sh

# Adds github issue number to commit message based on current branch name.
# Example: current branch '308-context-help', commit message 'fix bug', 
#          final commit message will be '#308 fix bug'

if [ "$NOPREFIX" ]; then
  exit 0
fi

number=$(git branch | grep '*' | sed 's/* //' | cut -d'-' -f 1) 
if [[ "$number" =~ ^[0-9]+$ ]] ; then
  echo '#'"$number"' '$(cat "$1") > "$1"
fi