Git count lines by author

gitcount.sh

#!/bin/sh
git log --shortstat | grep -E "(Author: )(\b\s*([A-Z]\w+)){2}|fil(e|es) changed" | awk '
{
 if($1 ~ /Author/) {
  author = $2" "$3
 } else {
  files[author]+=$1
  inserted[author]+=$4
  deleted[author]+=$6
 }
}
END { for (key in files) { print "Author: " key "\n\tfiles changed: ", files[key], "\n\tlines inserted: ", inserted[key], "\n\tlines deleted: ", deleted[key] } }
'

When I tried this script on a git repository, at least one Author was missing in the otherwise very nice result.

Yes, for us also many authors were missing, also Lines of Code are not shown with that script.

This script count also the merge commits. That's obvious, but unfortunately, it looks like someone's commit a lot, who doesn't. How can i filter by commit name?
--no-merges Doesn't seem to be working.

hello. That's very nice.
I think it needs a minor correction to handle lowercase names:

git log --shortstat | grep -E "(Author: )(\b\s*([a-zA-Z]\w+)){1,2}|fil(e|es) changed" | awk ' {

Thanks. Saved me lot of time. I have made some changes to get logs by month of an year. Added delta of additions and deletions. If no parameters are passed then logs are generated for current month. Invoking script with parameter all generates logs for all commits so far. Also incorporated gianpaolof fix for lowercase names.

#!/bin/bash

#inspired by https://gist.github.com/ezamelczyk/78b9c0dd095f8706a3f6a41e8eae0afd

if [ -z "$1" ]; then
    # Use current month
    set -- "$(date +%b)"
fi

if [ -z "$2" ]; then
    # Use current year
    set -- "$1" "$(date +%Y)"
fi

if [ "$1" != "all" ]; then
    # Filter by month and year
    # previous month as number
    pm=$(date -d "$1 1, $2 -1 month" +%m)
    # previous month as name
    pms=$(date -d "$1 1, $2 -1 month" +%b)
    # last day of previous month
    ld_pm=$(date -d "$pms 1, $2 +1 month -1 day" +%d)
    # next month as number
    nm=$(date -d "$1 1, $2 +1 month" +%m)
    after_year=$2
    before_year=$2
    if [ $pm -eq 12 ]; then
        # Decrement after year if previous month is December
        ((after_year--))
    fi
    if [ $nm -eq 01 ]; then
        # Increment before year if next month is January
        ((before_year++))
    fi
    filter="--after="$after_year-$pm-$ld_pm" --before="$before_year-$nm-01""
    msg="for $1 $2"
else
    # Get all logs
    filter=""
    msg="as of $(date "+%b %Y")"
fi

echo "" ; echo "Generating contribution log $msg ..." ; echo ""

git log --shortstat $filter | grep -E "(Author: )(\b\s*([a-zA-Z]\w+)){1,2}|fil(e|es) changed" | awk '
{
    if($1 ~ /Author/) {
        author = $2" "$3
    }
    else {
        files[author]+=$1
        inserted[author]+=$4
        deleted[author]+=$6
        delta[author]+=$4-$6
    }
}
END { for (key in files) { print "Author: " key "\n\tfiles changed: ", files[key], "\n\tlines inserted: ", inserted[key], "\n\tlines deleted: ", deleted[key], "\n\tlines delta: ", delta[key] } }
'

MacOS has their own 'date' utility with different syntax, so I put a test condition in so it will work the same on OSX or Linux.
Requires GNU date: brew install coreutils:

`#!/bin/bash
case $(uname -s) in
Linux*) datecmd=date;;
Darwin*) datecmd=gdate;;
*) datecmd=date;;
esac
#inspired by https://gist.github.com/ezamelczyk/78b9c0dd095f8706a3f6a41e8eae0afd

if [ -z "$1" ]; then
# Use current month
set -- "$(date +%b)"
fi

if [ -z "$2" ]; then
# Use current year
set -- "$1" "$(date +%Y)"
fi

if [ "$1" != "all" ]; then
# Filter by month and year
# previous month as number
pm=$($datecmd -d "$1 1, $2 -1 month" +%m)
# previous month as name
pms=$($datecmd -d "$1 1, $2 -1 month" +%b)
# last day of previous month
ld_pm=$($datecmd -d "$pms 1, $2 +1 month -1 day" +%d)
# next month as number
nm=$($datecmd -d "$1 1, $2 +1 month" +%m)
after_year=$2
before_year=$2
if [ $pm -eq 12 ]; then
# Decrement after year if previous month is December
((after_year--))
fi
if [ $nm -eq 01 ]; then
# Increment before year if next month is January
((before_year++))
fi
filter="--after="$after_year-$pm-$ld_pm" --before="$before_year-$nm-01""
msg="for $1 $2"
else
# Get all logs
filter=""
msg="as of $($datecmd "+%b %Y")"
fi

echo "" ; echo "Generating contribution log $msg ..." ; echo ""

git log --shortstat $filter | grep -E "(Author: )(\b\s*([a-zA-Z]\w+)){1,2}|fil(e|es) changed" | awk '
{
if($1 ~ /Author/) {
author = $2" "$3
}
else {
files[author]+=$1
inserted[author]+=$4
deleted[author]+=$6
delta[author]+=$4-$6
}
}
END { for (key in files) { print "Author: " key "\n\tfiles changed: ", files[key], "\n\tlines inserted: ", inserted[key], "\n\tlines deleted: ", deleted[key], "\n\tlines delta: ", delta[key] } }
'`

Updated version support for macOS without needing to install gdate utility

#!/bin/bash

#inspired by https://gist.github.com/ezamelczyk/78b9c0dd095f8706a3f6a41e8eae0afd

if [ -z "$1" ]; then
# Use current month
set -- "$(date +%b)"
fi

if [ -z "$2" ]; then
# Use current year
set -- "$1" "$(date +%Y)"
fi

echo "$1 $2"
if [ "$1" != "all" ]; then
# Filter by month and year
case $(uname -s) in
Darwin*)
    # previous month as number
    pm=$(date -j -v$1m -v1d -v$2y -v-1m +%m)
    # previous month as name
    pms=$(date -j -v$1m -v1d -v$2y -v-1m +%b)
    # last day of previous month
    ld_pm=$(date -j -v${pms}m -v1d -v$2y -v+1m -v1d +%b)
    # next month as number
    nm=$(date -j -v$1m -v1d -v$2y -v+1m +%m)
    ;;
*)
    # previous month as number
    pm=$(date -d "$1 1, $2 -1 month" +%m)
    # previous month as name
    pms=$(date -d "$1 1, $2 -1 month" +%b)
    # last day of previous month
    ld_pm=$(date -d "$pms 1, $2 +1 month -1 day" +%d)
    # next month as number
    nm=$(date -d "$1 1, $2 +1 month" +%m)
    ;;
esac
after_year=$2
before_year=$2
if [ $pm -eq 12 ]; then
# Decrement after year if previous month is December
((after_year--))
    fi
    if [ $nm -eq 01 ]; then
# Increment before year if next month is January
((before_year++))
    fi
    filter="--after="$after_year-$pm-$ld_pm" --before="$before_year-$nm-01""
    msg="for $1 $2"
    else
# Get all logs
    filter=""
    msg="as of $($datecmd "+%b %Y")"
    fi

    echo "" ; echo "Generating contribution log $msg ..." ; echo ""

    git log --shortstat $filter | grep -E "(Author: )(\b\s*([a-zA-Z]\w+)){1,2}|fil(e|es) changed" | awk '
{
    if($1 ~ /Author/) {
        author = $2" "$3
    }
    else {
        files[author]+=$1
            inserted[author]+=$4
            deleted[author]+=$6
            delta[author]+=$4-$6
    }
}
END { for (key in files) { print "Author: " key "\n\tfiles changed: ", files[key], "\n\tlines inserted: ", inserted[key], "\n\tlines deleted: ", deleted[key], "\n\tlines delta: ", delta[key] } }
'