gh-search

#!/bin/sh
set -e

#
# gh-search: Search for filetypes on GitHub
#
usage='Usage: gh-search [-p] [-e extension] [-f filename] [-l language] [query]'
unset ext name lang print
die()(printf >&2 "%s: %s\n" "${0##*/}" "$@"; exit 1)

while [ -n "$1" ]; do case $1 in
	-h|--help|-\?)
		printf '%s\n' "$usage"
		exit
	;;
	# Unbundle short options
	-[p]?*)
		tail="${1#??}"
		head=${1%"$tail"}
		shift
		set -- "$head" "-$tail" "$@"
		continue
	;;
	# Expand parametric values
	-[efnl]?*|--[!=]*=*)
		case $1 in
			--*) tail=${1#*=}; head=${1%%=*} ;;
			*)   tail=${1#??}; head=${1%"$tail"} ;;
		esac
		shift
		set -- "$head" "$tail" "$@"
		continue
	;;
	-p|--print)     print=1; ;;
	-e|--extension) ext=$2;  shift ;;
	-f|--filename)  name=$2; shift ;;
	-n|--name)      name=$2; shift ;;
	-l|--language)  lang=$2; shift ;;
	--)             shift; break   ;;
	-*) die "invalid option: '$1'" "$usage" ;;
	*) break ;;
esac; shift
done

# Bail if there's nothing to search for
[ "$ext$name$lang$print$1" ] || die 'no search query specified'

# Resolve conflicting option pairs
[ -z "$ext" ] || [ -z "$name" ] ||
	die 'extension and filename queries are mutually exclusive'

# Resolve search qualifiers
unset query
[ -z "$ext"  ] || query="path:**/?*.${ext#.}"
[ -z "$name" ] || query="path:**/$name"
[ -z "$lang" ] || query="$query language:\"$lang\""

# Append any additional query parameters
while [ $# -gt 0 ]; do
	case $1 in
		*\ *) query="$query \"$1\"" ;;
		*?*)  query="$query $1" ;;
	esac
	shift
done

set -- "https://github.com/search?q=`printf %s "${query# }" | sed '
	s/%/%25/g
	s/:/%3A/g
	s,/,%2F,g
	s/?/%3F/g
	s/&/%26/g
	s/+/%2B/g
	s/[[:blank:]]\{1,\}/+/g
'`&type=code"

# Print search url if `--print` was passed
[ -z "$print" ] || {
	printf '%s\n' "$1"
	exit
}

case `uname -s` in
	Darwin) open "$@" ;;
	*)      xdg-open "$@" ;;
esac