Simple bash script to count effective lines of code for several types of languages

countlines.sh

#!/bin/bash
# count lines of code, excluding comments and empty lines.
# (c) silverweed - released under Public Domain

comment_style() {
	local CS=''
	case $1 in
	c|cpp|cs|java*|js) CS='^\s*//|^\s*\*|^\s*/\*' ;;
	sh|bash|zsh|ruby|py*) CS='^\s*#' ;;
	lua) CS='--' ;;
	hs|haskell) CS='--|^\s*{-'
	esac
	[[ -n $CS ]] && echo "(^\\s*$|$CS)" || echo '^\s*$'
}

COMMENT_STYLE=$(comment_style c)

while [[ $# > 0 ]]; do
	case $1 in
	-h) echo "Usage: $0 [-e ext] [-c <comment-style, default=c>] [--exclude path] [dir]" >&2; exit 0 ;;
	-e) shift; EXT=$1; shift ;;
	-c) shift; COMMENT_STYLE=$(comment_style $1); shift ;;
	--exclude) shift; EXCLUDE="-not -path $1"; shift ;;
	*) DIR+="$1 "; shift ;;
	esac
done
DIR=${DIR:-.}

find $DIR -type f -name \*$EXT $EXCLUDE -exec grep -cvE $COMMENT_STYLE {} + |
	tee >(awk -v FS=':' '{printf "%-5d %s\n", $2, $1}' | sort -g >&2) |
	cut -f2 -d: |
	awk '{ n += $1 } END { print n }'