Shell Script to Compare Recent Git Branches

recent-branches

#!/bin/bash

# function definition to print out help text
showHelp() {
cat << EOF
Usage: ./recent-branches -b <target-branch> -n <number-of-branches> [-hrl]
Analyzes the most recent (or oldest branches) in a repository, as well as how
many commits ahead or behind it is from a target branch

-h  Display help
-n  Number of branches to output (default: 10)
-b  Target branch to compare against (default is default branch)
-r  Reverse sort order (default: most recent first)
-l  Use local branches instead of remote origin

EOF
}

# get the default branch
defaultbranch=$(git remote show origin | sed -n '/HEAD branch/s/.*: //p')

# set some defaults...
refbranch=$defaultbranch
count=10
sort="-committerdate"
pattern="refs/remotes/origin/"
strip=3

# parse the option arguments
while getopts ":hn::b::orl" option; do
  case $option in
    h) # display Help
      showHelp
      exit
      ;;
    n) # enter a number
      count=$OPTARG
      ;;
    b) # enter a branch
      refbranch=$OPTARG
      ;;
    r) # reverse
      sort="committerdate"
      ;;
    l) # use local branches
      pattern="refs/heads/"
      strip=2
      ;;
    *)
      echo "Internal error!"
      exit 1
      ;;
  esac
done

# string that will be interpolated by the git for-each-ref below
# this forms a large fragment of the final output
format="%(refname:short)|"
format+="%(color:yellow)%(refname:lstrip=$strip)|"
format+="%(color:cyan)%(committerdate:relative)|"
format+="%(color:magenta)%(authorname)|"
format+="%(color:blue)%(subject)%(color:reset)"

# a header string
header="\033[37mBEHIND|"
header+="\033[37mAHEAD|"
header+="\033[37mBRANCH|"
header+="\033[37mLASTCOMMIT|"
header+="\033[37mAUTHOR|"
header+="\033[37mMESSAGE"

echo -e "━━━━━━━━━━━━━━━━━━"
echo -e "COMPARING AGAINST: \033[31m$refbranch\033[0m"
echo -e "━━━━━━━━━━━━━━━━━━"

# loop over and process the output information on each git ref (branch)
# THEN append the headers
# THEN format the lines as columns
git for-each-ref \
  --sort=${sort} \
  ${pattern} \
  --format="${format}" \
  --color=always \
  --count=${count} \
  | while read line; do
    # parse the first refname to determine the current branch
    branch=$(echo "$line" | awk 'BEGIN { FS = "|" }; { print $1 }' | tr -d '*');

    # parse how far ahead or behind the current branch is
    behind="\033[31m--$(git rev-list --count "${branch}..${refbranch}")"
    ahead="\033[32m++$(git rev-list --count "${refbranch}..${branch}")"

    # remove the first refname from the line information
    colorline=$(echo "$line" | sed 's/^[^|]*|//');

    # combine into a single line
    # also enforce a max lenght of 70 characters for the git message column
    echo -e "$behind|$ahead|$colorline" | awk -F'|' -vOFS='|' '{if (length($6)>70) $6=substr($6,1,70) "\033[0m"}1';
  done \
  | ( echo -e "$header\n" && cat) \
  | column -ts'|'
  
# REFERENCE
# https://stackoverflow.com/questions/5188320/how-can-i-get-a-list-of-git-branches-ordered-by-most-recent-commit
#
# ORIGINAL IMPLEMENTATION
# [alias]
#     # ATTENTION: All aliases prefixed with ! run in /bin/sh make sure you use sh syntax, not bash/zsh or whatever
#     recentb = "!r() { refbranch=$1 count=$2; git for-each-ref --sort=-committerdate refs/heads --format='%(refname:short)|%(HEAD)%(color:yellow)%(refname:short)|%(color:bold green)%(committerdate:relative)|%(color:blue)%(subject)|%(color:magenta)%(authorname)%(color:reset)' --color=always --count=${count:-20} | while read line; do branch=$(echo \"$line\" | awk 'BEGIN { FS = \"|\" }; { print $1 }' | tr -d '*'); ahead=$(git rev-list --count \"${refbranch:-origin/master}..${branch}\"); behind=$(git rev-list --count \"${branch}..${refbranch:-origin/master}\"); colorline=$(echo \"$line\" | sed 's/^[^|]*|//'); echo \"$ahead|$behind|$colorline\" | awk -F'|' -vOFS='|' '{$5=substr($5,1,70)}1' ; done | ( echo \"ahead|behind|branch|lastcommit|message|author\n\" && cat) | column -ts'|';}; r"
#
# REFORMATTED ORIGINAL
# refbranch=$1
# count=$2;
# git for-each-ref --sort=-committerdate refs/heads \
#   --format='%(refname:short)|%(HEAD)%(color:yellow)%(refname:short)|%(color:bold green)%(committerdate:relative)|%(color:blue)%(subject)|%(color:magenta)%(authorname)%(color:reset)' \
#   --color=always --count=${count:-20} \
#   | while read line; do \
#     branch=$(echo "$line"s | awk 'BEGIN { FS = "|" }; { print $1 }' | tr -d '*'); \
#     ahead=$(git rev-list --count "${refbranch:-origin/master}..${branch}"); \
#     behind=$(git rev-list --count "${branch}..${refbranch:-origin/master}"); \
#     colorline=$(echo "$line" | sed 's/^[^|]*|//'); \
#     echo "$ahead|$behind|$colorline" | awk -F'|' -vOFS='|' '{$5=substr($5,1,70)}1' ;
#   done \
#   | ( echo "ahead|behind|branch|lastcommit|message|author\n" && cat) \
#   | column -ts'|'