#!/bin/sh
#
# Closely (not perfectly) emulate the behavior of glibc's getent utility
#
#passwd|shadow|group|aliases|hosts|networks|ethers|netgroup|protocols|services|rpc
# only returns the first match (by design)
# dns based search is not supported (hosts,networks)
# case-insensitive matches not supported (ethers; others?)
# may return false-positives (hosts,protocols,rpc,services,ethers)

[ -z "$PATH" ] && PATH="/bin:/usr/bin" || PATH="${PATH}:/bin:/usr/bin"
export PATH

file="/etc/$1"
case $1 in
	passwd|group)
		match="^$2:\|^[^:]*:[^:]*:$2:" ;;
	shadow)
		match="^$2:" ;;
	networks|netgroup)
		match="^[[:space:]]*$2\>" ;;
	hosts|protocols|rpc|services|ethers)
		match="\<$2\>" ;;
	aliases)
		match="^[[:space:]]*$2[[:space:]]*:" ;;
	""|-h|--help)
		echo "USAGE: $0 database [key]"
		exit 0 ;;
	*)
		echo "$0: Unknown database: $1" 1>&2
		exit 1 ;;
esac

if [ ! -f "$file" ] ; then
	echo "$0: Could not find database file for $1" 1>&2
	exit 1
fi

if [ $# -eq 1 ] ; then
	exec cat "$file"
else
	sed "s/#.*//; /$match/q; d" "$file" | grep . || exit 2
fi
