# Copyright 1999-2007 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: /var/cvsroot/gentoo-x86/eclass/eutils.eclass,v 1.298 2008/02/20 12:36:14 hollow Exp $

# @ECLASS: eutils.eclass
# @MAINTAINER:
# base-system@gentoo.org
# @BLURB: many extra (but common) functions that are used in ebuilds
# @DESCRIPTION:
# The eutils eclass contains a suite of functions that complement
# the ones that ebuild.sh already contain.  The idea is that the functions
# are not required in all ebuilds but enough utilize them to have a common
# home rather than having multiple ebuilds implementing the same thing.
#
# Due to the nature of this eclass, some functions may have maintainers
# different from the overall eclass!

inherit multilib portability

DESCRIPTION="Based on the ${ECLASS} eclass"

# @FUNCTION: epause
# @USAGE: [seconds]
# @DESCRIPTION:
# Sleep for the specified number of seconds (default of 5 seconds).  Useful when
# printing a message the user should probably be reading and often used in
# conjunction with the ebeep function.  If the EPAUSE_IGNORE env var is set,
# don't wait at all.
epause() {
	[[ -z ${EPAUSE_IGNORE} ]] && sleep ${1:-5}
}

# @FUNCTION: ebeep
# @USAGE: [number of beeps]
# @DESCRIPTION:
# Issue the specified number of beeps (default of 5 beeps).  Useful when
# printing a message the user should probably be reading and often used in
# conjunction with the epause function.  If the EBEEP_IGNORE env var is set,
# don't beep at all.
ebeep() {
	local n
	if [[ -z ${EBEEP_IGNORE} ]] ; then
		for ((n=1 ; n <= ${1:-5} ; n++)) ; do
			echo -ne "\a"
			sleep 0.1 &>/dev/null ; sleep 0,1 &>/dev/null
			echo -ne "\a"
			sleep 1
		done
	fi
}

# @FUNCTION: ecvs_clean
# @USAGE: <dir> [more dirs ...]
# @DESCRIPTION:
# Remove CVS directories recursiveley. Useful when a source tarball contains
# internal CVS directories.
ecvs_clean() {
	[[ $# -gt 0 ]] || set -- .
	find "$@" -type d -name 'CVS' -prune -print0 | xargs -0 rm -rf
	find "$@" -type f -name '.cvs*' -print0 | xargs -0 rm -rf
}

# @FUNCTION: esvn_clean
# @USAGE: <dir> [more dirs ...]
# @DESCRIPTION:
# Remove .svn directories recursiveley. Useful when a source tarball contains
# internal Subversion directories.
esvn_clean() {
	[[ $# -gt 0 ]] || set -- .
	find "$@" -type d -name '.svn' -prune -print0 | xargs -0 rm -rf
}

# Default directory where patches are located
EPATCH_SOURCE="${WORKDIR}/patch"
# Default extension for patches
EPATCH_SUFFIX="patch.bz2"
# Default options for patch
# Set -g0 to keep RCS, ClearCase, Perforce and SCCS happy. Bug #24571
# Set --no-backup-if-mismatch so we don't leave '.orig' files behind.
# Set -E to automatically remove empty files.
EPATCH_OPTS="-g0 -E --no-backup-if-mismatch"
# List of patches not to apply.	 Not this is only file names,
# and not the full path ..
EPATCH_EXCLUDE=""
# Change the printed message for a single patch.
EPATCH_SINGLE_MSG=""
# Change the printed message for multiple patches.
EPATCH_MULTI_MSG="Applying various patches (bugfixes/updates) ..."
# Force applying bulk patches even if not following the style:
#
#	??_${ARCH}_foo.${EPATCH_SUFFIX}
#
EPATCH_FORCE="no"

# This function is for bulk patching, or in theory for just one
# or two patches.
#
# It should work with .bz2, .gz, .zip and plain text patches.
# Currently all patches should be the same format.
#
# You do not have to specify '-p' option to patch, as it will
# try with -p0 to -p5 until it succeed, or fail at -p5.
#
# Above EPATCH_* variables can be used to control various defaults,
# bug they should be left as is to ensure an ebuild can rely on
# them for.
#
# Patches are applied in current directory.
#
# Bulk Patches should preferibly have the form of:
#
#	??_${ARCH}_foo.${EPATCH_SUFFIX}
#
# For example:
#
#	01_all_misc-fix.patch.bz2
#	02_sparc_another-fix.patch.bz2
#
# This ensures that there are a set order, and you can have ARCH
# specific patches.
#
# If you however give an argument to epatch(), it will treat it as a
# single patch that need to be applied if its a file.  If on the other
# hand its a directory, it will set EPATCH_SOURCE to this.
#
# <azarah@gentoo.org> (10 Nov 2002)
#
epatch() {
	_epatch_draw_line() {
		[[ -z $1 ]] && set "$(printf "%65s" '')"
		echo "${1//?/=}"
	}
	_epatch_assert() { local _pipestatus=${PIPESTATUS[*]}; [[ ${_pipestatus// /} -eq 0 ]] ; }
	local PIPE_CMD=""
	local STDERR_TARGET="${T}/$$.out"
	local PATCH_TARGET="${T}/$$.patch"
	local PATCH_SUFFIX=""
	local SINGLE_PATCH="no"
	local x=""

	unset P4CONFIG P4PORT P4USER # keep perforce at bay #56402

	if [ "$#" -gt 1 ]
	then
		local m=""
		for m in "$@" ; do
			epatch "${m}"
		done
		return 0
	fi

	if [ -n "$1" -a -f "$1" ]
	then
		SINGLE_PATCH="yes"

		local EPATCH_SOURCE="$1"
		local EPATCH_SUFFIX="${1##*\.}"

	elif [ -n "$1" -a -d "$1" ]
	then
		# Allow no extension if EPATCH_FORCE=yes ... used by vim for example ...
		if [ "${EPATCH_FORCE}" = "yes" ] && [ -z "${EPATCH_SUFFIX}" ]
		then
			local EPATCH_SOURCE="$1/*"
		else
			local EPATCH_SOURCE="$1/*.${EPATCH_SUFFIX}"
		fi
	else
		if [[ ! -d ${EPATCH_SOURCE} ]] || [[ -n $1 ]] ; then
			if [ -n "$1" -a "${EPATCH_SOURCE}" = "${WORKDIR}/patch" ]
			then
				EPATCH_SOURCE="$1"
			fi

			echo
			eerror "Cannot find \$EPATCH_SOURCE!  Value for \$EPATCH_SOURCE is:"
			eerror
			eerror "  ${EPATCH_SOURCE}"
			eerror "  ( ${EPATCH_SOURCE##*/} )"
			echo
			die "Cannot find \$EPATCH_SOURCE!"
		fi

		local EPATCH_SOURCE="${EPATCH_SOURCE}/*.${EPATCH_SUFFIX}"
	fi

	case ${EPATCH_SUFFIX##*\.} in
		bz2)
			PIPE_CMD="bzip2 -dc"
			PATCH_SUFFIX="bz2"
			;;
		gz|Z|z)
			PIPE_CMD="gzip -dc"
			PATCH_SUFFIX="gz"
			;;
		ZIP|zip)
			PIPE_CMD="unzip -p"
			PATCH_SUFFIX="zip"
			;;
		*)
			PIPE_CMD="cat"
			PATCH_SUFFIX="patch"
			;;
	esac

	if [ "${SINGLE_PATCH}" = "no" ]
	then
		einfo "${EPATCH_MULTI_MSG}"
	fi
	for x in ${EPATCH_SOURCE}
	do
		# New ARCH dependant patch naming scheme ...
		#
		#	???_arch_foo.patch
		#
		if [ -f ${x} ] && \
		   ([ "${SINGLE_PATCH}" = "yes" -o "${x/_all_}" != "${x}" -o "${x/_${ARCH}_}" != "${x}" ] || \
			[ "${EPATCH_FORCE}" = "yes" ])
		then
			local count=0
			local popts="${EPATCH_OPTS}"
			local patchname=${x##*/}

			if [ -n "${EPATCH_EXCLUDE}" ]
			then
				if [ "${EPATCH_EXCLUDE/${patchname}}" != "${EPATCH_EXCLUDE}" ]
				then
					continue
				fi
			fi

			if [ "${SINGLE_PATCH}" = "yes" ]
			then
				if [ -n "${EPATCH_SINGLE_MSG}" ]
				then
					einfo "${EPATCH_SINGLE_MSG}"
				else
					einfo "Applying ${patchname} ..."
				fi
			else
				einfo "  ${patchname} ..."
			fi

			echo "***** ${patchname} *****" > ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}
			echo >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}

			# Allow for prefix to differ ... im lazy, so shoot me :/
			while [ "${count}" -lt 5 ]
			do
				# Generate some useful debug info ...
				_epatch_draw_line "***** ${patchname} *****" >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}
				echo >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}

				if [ "${PATCH_SUFFIX}" != "patch" ]
				then
					echo -n "PIPE_COMMAND:	" >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}
					echo "${PIPE_CMD} ${x} > ${PATCH_TARGET}" >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}
				else
					PATCH_TARGET="${x}"
				fi

				echo -n "PATCH COMMAND:	 " >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}
				echo "patch -p${count} ${popts} < ${PATCH_TARGET}" >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}

				echo >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}
				_epatch_draw_line "***** ${patchname} *****" >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}

				if [ "${PATCH_SUFFIX}" != "patch" ]
				then
					if ! (${PIPE_CMD} ${x} > ${PATCH_TARGET}) >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/} 2>&1
					then
						echo
						eerror "Could not extract patch!"
						#die "Could not extract patch!"
						count=5
						break
					fi
				fi

				if (cat ${PATCH_TARGET} | patch -p${count} ${popts} --dry-run -f ; _epatch_assert) >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/} 2>&1
				then
					_epatch_draw_line "***** ${patchname} *****" >	${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}.real
					echo >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}.real
					echo "ACTUALLY APPLYING ${patchname} ..." >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}.real
					echo >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}.real
					_epatch_draw_line "***** ${patchname} *****" >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}.real

					cat ${PATCH_TARGET} | patch -p${count} ${popts} >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}.real 2>&1
					_epatch_assert

					if [ "$?" -ne 0 ]
					then
						cat ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}.real >> ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}
						echo
						eerror "A dry-run of patch command succeeded, but actually"
						eerror "applying the patch failed!"
						#die "Real world sux compared to the dreamworld!"
						count=5
					fi

					rm -f ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}.real

					break
				fi

				count=$((count + 1))
			done

			if [ "${PATCH_SUFFIX}" != "patch" ]
			then
				rm -f ${PATCH_TARGET}
			fi

			if [ "${count}" -eq 5 ]
			then
				echo
				eerror "Failed Patch: ${patchname} !"
				eerror " ( ${PATCH_TARGET} )"
				eerror
				eerror "Include in your bugreport the contents of:"
				eerror
				eerror "  ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}"
				echo
				die "Failed Patch: ${patchname}!"
			fi

			rm -f ${STDERR_TARGET%/*}/${patchname}-${STDERR_TARGET##*/}

			eend 0
		fi
	done
	if [ "${SINGLE_PATCH}" = "no" ]
	then
		einfo "Done with patching"
	fi
}

# @FUNCTION: emktemp
# @USAGE: [temp dir]
# @DESCRIPTION:
# Cheap replacement for when debianutils (and thus mktemp)
# does not exist on the users system.
emktemp() {
	local exe="touch"
	[[ $1 == -d ]] && exe="mkdir" && shift
	local topdir=$1

	if [[ -z ${topdir} ]] ; then
		[[ -z ${T} ]] \
			&& topdir="/tmp" \
			|| topdir=${T}
	fi

	if ! type -P mktemp > /dev/null ; then
		# system lacks `mktemp` so we have to fake it
		local tmp=/
		while [[ -e ${tmp} ]] ; do
			tmp=${topdir}/tmp.${RANDOM}.${RANDOM}.${RANDOM}
		done
		${exe} "${tmp}" || ${exe} -p "${tmp}"
		echo "${tmp}"
	else
		# the args here will give slightly wierd names on BSD,
		# but should produce a usable file on all userlands
		if [[ ${exe} == "touch" ]] ; then
			TMPDIR="${topdir}" mktemp -t tmp.XXXXXXXXXX
		else
			TMPDIR="${topdir}" mktemp -dt tmp.XXXXXXXXXX
		fi
	fi
}

# @FUNCTION: egetent
# @USAGE: <database> <key>
# @MAINTAINER:
# base-system@gentoo.org (Linux)
# Joe Jezak <josejx@gmail.com> (OS X)
# usata@gentoo.org (OS X)
# Aaron Walker <ka0ttic@gentoo.org> (FreeBSD)
# @DESCRIPTION:
# Small wrapper for getent (Linux), nidump (Mac OS X),
# and pw (FreeBSD) used in enewuser()/enewgroup()
egetent() {
	case ${CHOST} in
	*-darwin*)
		case "$2" in
		*[!0-9]*) # Non numeric
			nidump $1 . | awk -F":" "{ if (\$1 ~ /^$2$/) {print \$0;exit;} }"
			;;
		*)	# Numeric
			nidump $1 . | awk -F":" "{ if (\$3 == $2) {print \$0;exit;} }"
			;;
		esac
		;;
	*-freebsd*|*-dragonfly*)
		local opts action="user"
		[[ $1 == "passwd" ]] || action="group"

		# lookup by uid/gid
		if [[ $2 == [[:digit:]]* ]] ; then
			[[ ${action} == "user" ]] && opts="-u" || opts="-g"
		fi

		pw show ${action} ${opts} "$2" -q
		;;
	*-netbsd*|*-openbsd*)
		grep "$2:\*:" /etc/$1
		;;
	*)
		type -p nscd >& /dev/null && nscd -i "$1"
		getent "$1" "$2"
		;;
	esac
}

# @FUNCTION: enewuser
# @USAGE: <user> [uid] [shell] [homedir] [groups] [params]
# @DESCRIPTION:
# Same as enewgroup, you are not required to understand how to properly add
# a user to the system.  The only required parameter is the username.
# Default uid is (pass -1 for this) next available, default shell is
# /bin/false, default homedir is /dev/null, there are no default groups,
# and default params sets the comment as 'added by portage for ${PN}'.
enewuser() {
	case ${EBUILD_PHASE} in
		unpack|compile|test|install)
		eerror "'enewuser()' called from '${EBUILD_PHASE}()' which is not a pkg_* function."
		eerror "Package fails at QA and at life.  Please file a bug."
		die "Bad package!  enewuser is only for use in pkg_* functions!"
	esac

	# get the username
	local euser=$1; shift
	if [[ -z ${euser} ]] ; then
		eerror "No username specified !"
		die "Cannot call enewuser without a username"
	fi

	# lets see if the username already exists
	if [[ -n $(egetent passwd "${euser}") ]] ; then
		return 0
	fi
	einfo "Adding user '${euser}' to your system ..."

	# options to pass to useradd
	local opts=

	# handle uid
	local euid=$1; shift
	if [[ -n ${euid} && ${euid} != -1 ]] ; then
		if [[ ${euid} -gt 0 ]] ; then
			if [[ -n $(egetent passwd ${euid}) ]] ; then
				euid="next"
			fi
		else
			eerror "Userid given but is not greater than 0 !"
			die "${euid} is not a valid UID"
		fi
	else
		euid="next"
	fi
	if [[ ${euid} == "next" ]] ; then
		for ((euid = 101; euid <= 999; euid++)); do
			[[ -z $(egetent passwd ${euid}) ]] && break
		done
	fi
	opts="${opts} -u ${euid}"
	einfo " - Userid: ${euid}"

	# handle shell
	local eshell=$1; shift
	if [[ ! -z ${eshell} ]] && [[ ${eshell} != "-1" ]] ; then
		if [[ ! -e ${ROOT}${eshell} ]] ; then
			eerror "A shell was specified but it does not exist !"
			die "${eshell} does not exist in ${ROOT}"
		fi
		if [[ ${eshell} == */false || ${eshell} == */nologin ]] ; then
			eerror "Do not specify ${eshell} yourself, use -1"
			die "Pass '-1' as the shell parameter"
		fi
	else
		for shell in /sbin/nologin /usr/sbin/nologin /bin/false /usr/bin/false /dev/null ; do
			[[ -x ${ROOT}${shell} ]] && break
		done

		if [[ ${shell} == "/dev/null" ]] ; then
			eerror "Unable to identify the shell to use, proceeding with userland default."
			case ${USERLAND} in
				GNU) shell="/bin/false" ;;
				BSD) shell="/sbin/nologin" ;;
				Darwin) shell="/usr/sbin/nologin" ;;
				*) die "Unable to identify the default shell for userland ${USERLAND}"
			esac
		fi

		eshell=${shell}
	fi
	einfo " - Shell: ${eshell}"
	opts="${opts} -s ${eshell}"

	# handle homedir
	local ehome=$1; shift
	if [[ -z ${ehome} ]] || [[ ${ehome} == "-1" ]] ; then
		ehome="/dev/null"
	fi
	einfo " - Home: ${ehome}"
	opts="${opts} -d ${ehome}"

	# handle groups
	local egroups=$1; shift
	if [[ ! -z ${egroups} ]] ; then
		local oldifs=${IFS}
		local defgroup="" exgroups=""

		export IFS=","
		for g in ${egroups} ; do
			export IFS=${oldifs}
			if [[ -z $(egetent group "${g}") ]] ; then
				eerror "You must add group ${g} to the system first"
				die "${g} is not a valid GID"
			fi
			if [[ -z ${defgroup} ]] ; then
				defgroup=${g}
			else
				exgroups="${exgroups},${g}"
			fi
			export IFS=","
		done
		export IFS=${oldifs}

		opts="${opts} -g ${defgroup}"
		if [[ ! -z ${exgroups} ]] ; then
			opts="${opts} -G ${exgroups:1}"
		fi
	else
		egroups="(none)"
	fi
	einfo " - Groups: ${egroups}"

	# handle extra and add the user
	local oldsandbox=${SANDBOX_ON}
	export SANDBOX_ON="0"
	case ${CHOST} in
	*-darwin*)
		### Make the user
		if [[ -z $@ ]] ; then
			dscl . create /users/${euser} uid ${euid}
			dscl . create /users/${euser} shell ${eshell}
			dscl . create /users/${euser} home ${ehome}
			dscl . create /users/${euser} realname "added by portage for ${PN}"
			### Add the user to the groups specified
			local oldifs=${IFS}
			export IFS=","
			for g in ${egroups} ; do
				dscl . merge /groups/${g} users ${euser}
			done
			export IFS=${oldifs}
		else
			einfo "Extra options are not supported on Darwin yet"
			einfo "Please report the ebuild along with the info below"
			einfo "eextra: $@"
			die "Required function missing"
		fi
		;;
	*-freebsd*|*-dragonfly*)
		if [[ -z $@ ]] ; then
			pw useradd ${euser} ${opts} \
				-c "added by portage for ${PN}" \
				die "enewuser failed"
		else
			einfo " - Extra: $@"
			pw useradd ${euser} ${opts} \
				"$@" || die "enewuser failed"
		fi
		;;

	*-netbsd*)
		if [[ -z $@ ]] ; then
			useradd ${opts} ${euser} || die "enewuser failed"
		else
			einfo " - Extra: $@"
			useradd ${opts} ${euser} "$@" || die "enewuser failed"
		fi
		;;

	*-openbsd*)
		if [[ -z $@ ]] ; then
			useradd -u ${euid} -s ${eshell} \
				-d ${ehome} -c "Added by portage for ${PN}" \
				-g ${egroups} ${euser} || die "enewuser failed"
		else
			einfo " - Extra: $@"
			useradd -u ${euid} -s ${eshell} \
				-d ${ehome} -c "Added by portage for ${PN}" \
				-g ${egroups} ${euser} "$@" || die "enewuser failed"
		fi
		;;

	*)
		if [[ -z $@ ]] ; then
			useradd ${opts} ${euser} \
				-c "added by portage for ${PN}" \
				|| die "enewuser failed"
		else
			einfo " - Extra: $@"
			useradd ${opts} ${euser} "$@" \
				|| die "enewuser failed"
		fi
		;;
	esac

	if [[ ! -e ${ROOT}/${ehome} ]] ; then
		einfo " - Creating ${ehome} in ${ROOT}"
		mkdir -p "${ROOT}/${ehome}"
		chown ${euser} "${ROOT}/${ehome}"
		chmod 755 "${ROOT}/${ehome}"
	fi

	export SANDBOX_ON=${oldsandbox}
}

# @FUNCTION: enewgroup
# @USAGE: <group> [gid]
# @DESCRIPTION:
# This function does not require you to understand how to properly add a
# group to the system.  Just give it a group name to add and enewgroup will
# do the rest.  You may specify the gid for the group or allow the group to
# allocate the next available one.
enewgroup() {
	case ${EBUILD_PHASE} in
		unpack|compile|test|install)
		eerror "'enewgroup()' called from '${EBUILD_PHASE}()' which is not a pkg_* function."
		eerror "Package fails at QA and at life.  Please file a bug."
		die "Bad package!  enewgroup is only for use in pkg_* functions!"
	esac

	# get the group
	local egroup="$1"; shift
	if [ -z "${egroup}" ]
	then
		eerror "No group specified !"
		die "Cannot call enewgroup without a group"
	fi

	# see if group already exists
	if [[ -n $(egetent group "${egroup}") ]]; then
		return 0
	fi
	einfo "Adding group '${egroup}' to your system ..."

	# options to pass to useradd
	local opts=

	# handle gid
	local egid="$1"; shift
	if [ ! -z "${egid}" ]
	then
		if [ "${egid}" -gt 0 ]
		then
			if [ -z "`egetent group ${egid}`" ]
			then
				if [[ "${CHOST}" == *-darwin* ]]; then
					opts="${opts} ${egid}"
				else
					opts="${opts} -g ${egid}"
				fi
			else
				egid="next available; requested gid taken"
			fi
		else
			eerror "Groupid given but is not greater than 0 !"
			die "${egid} is not a valid GID"
		fi
	else
		egid="next available"
	fi
	einfo " - Groupid: ${egid}"

	# handle extra
	local eextra="$@"
	opts="${opts} ${eextra}"

	# add the group
	local oldsandbox="${SANDBOX_ON}"
	export SANDBOX_ON="0"
	case ${CHOST} in
	*-darwin*)
		if [ ! -z "${eextra}" ];
		then
			einfo "Extra options are not supported on Darwin/OS X yet"
			einfo "Please report the ebuild along with the info below"
			einfo "eextra: ${eextra}"
			die "Required function missing"
		fi

		# If we need the next available
		case ${egid} in
		*[!0-9]*) # Non numeric
			for ((egid = 101; egid <= 999; egid++)); do
				[[ -z $(egetent group ${egid}) ]] && break
			done
		esac
		dscl . create /groups/${egroup} gid ${egid}
		dscl . create /groups/${egroup} passwd '*'
		;;

	*-freebsd*|*-dragonfly*)
		case ${egid} in
			*[!0-9]*) # Non numeric
				for ((egid = 101; egid <= 999; egid++)); do
					[[ -z $(egetent group ${egid}) ]] && break
				done
		esac
		pw groupadd ${egroup} -g ${egid} || die "enewgroup failed"
		;;

	*-netbsd*)
		case ${egid} in
		*[!0-9]*) # Non numeric
			for ((egid = 101; egid <= 999; egid++)); do
				[[ -z $(egetent group ${egid}) ]] && break
			done
		esac
		groupadd -g ${egid} ${egroup} || die "enewgroup failed"
		;;

	*)
		groupadd ${opts} ${egroup} || die "enewgroup failed"
		;;
	esac
	export SANDBOX_ON="${oldsandbox}"
}

# @FUNCTION: edos2unix
# @USAGE: <file> [more files ...]
# @DESCRIPTION:
# A handy replacement for dos2unix, recode, fixdos, etc...  This allows you
# to remove all of these text utilities from DEPEND variables because this
# is a script based solution.  Just give it a list of files to convert and
# they will all be changed from the DOS CRLF format to the UNIX LF format.
edos2unix() {
	echo "$@" | xargs sed -i 's/\r$//'
}

# Make a desktop file !
# Great for making those icons in kde/gnome startmenu !
# Amaze your friends !	Get the women !	 Join today !
#
# make_desktop_entry(<command>, [name], [icon], [type], [path])
#
# binary:	what command does the app run with ?
# name:		the name that will show up in the menu
# icon:		give your little like a pretty little icon ...
#			this can be relative (to /usr/share/pixmaps) or
#			a full path to an icon
# type:		what kind of application is this ?	for categories:
#			http://standards.freedesktop.org/menu-spec/latest/apa.html
# path:		if your app needs to startup in a specific dir
make_desktop_entry() {
	[[ -z $1 ]] && eerror "make_desktop_entry: You must specify the executable" && return 1

	local exec=${1}
	local name=${2:-${PN}}
	local icon=${3:-${PN}}
	local type=${4}
	local path=${5}

	if [[ -z ${type} ]] ; then
		local catmaj=${CATEGORY%%-*}
		local catmin=${CATEGORY##*-}
		case ${catmaj} in
			app)
				case ${catmin} in
					accessibility) type=Accessibility;;
					admin)	   type=System;;
					antivirus) type=System;;
					arch)      type=Archiving;;
					backup)    type=Archiving;;
					cdr)	   type=DiscBurning;;
					dicts)	   type=Dictionary;;
					doc)       type=Documentation;;
					editors)   type=TextEditor;;
					emacs)	   type=TextEditor;;
					emulation) type=Emulator;;
					laptop)	   type=HardwareSettings;;
					office)	   type=Office;;
					pda)       type=PDA;;
					vim)	   type=TextEditor;;
					xemacs)	   type=TextEditor;;
					*)		   type=;;
				esac
				;;

			dev)
				type="Development"
				;;

			games)
				case ${catmin} in
					action|fps) type=ActionGame;;
					arcade)		type=ArcadeGame;;
					board)		type=BoardGame;;
					emulation)	type=Emulator;;
					kids)		type=KidsGame;;
					puzzle)		type=LogicGame;;
					roguelike)	type=RolePlaying;;
					rpg)		type=RolePlaying;;
					simulation) type=Simulation;;
					sports)		type=SportsGame;;
					strategy)	type=StrategyGame;;
					*)			type=;;
				esac
				type="Game;${type}"
				;;

			gnome)
				type="Gnome;GTK"
				;;

			kde)
				type="KDE;Qt"
				;;

			mail)
				type="Network;Email"
				;;

			media)
				case ${catmin} in
					gfx)   type=Graphics;;
					radio) type=Tuner;;
					sound) type=Audio;;
					tv)	   type=TV;;
					video) type=Video;;
					*)	   type=;;
				esac
				type="AudioVideo;${type}"
				;;

			net)
				case ${catmin} in
					dialup) type=Dialup;;
					ftp)	type=FileTransfer;;
					im)		type=InstantMessaging;;
					irc)	type=IRCClient;;
					mail)	type=Email;;
					news)	type=News;;
					nntp)	type=News;;
					p2p)	type=FileTransfer;;
					*)		type=;;
				esac
				type="Network;${type}"
				;;

			sci)
				case ${catmin} in
					astro*)  type=Astronomy;;
					bio*)	 type=Biology;;
					calc*)	 type=Calculator;;
					chem*)	 type=Chemistry;;
					elec*)   type=Electronics;;
					geo*)	 type=Geology;;
					math*)	 type=Math;;
					physics) type=Physics;;
					visual*) type=DataVisualization;;
					*)		 type=;;
				esac
				type="Science;${type}"
				;;

			sys)
				type="System"
				;;

			www)
				case ${catmin} in
					client) type=WebBrowser;;
					*)		type=;;
				esac
				type="Network"
				;;

			*)
				type=
				;;
		esac
	fi
	if [ "${SLOT}" == "0" ] ; then
		local desktop_name="${PN}"
	else
		local desktop_name="${PN}-${SLOT}"
	fi
	local desktop="${T}/$(echo ${exec} | sed 's:[[:space:]/:]:_:g')-${desktop_name}.desktop"
	#local desktop=${T}/${exec%% *:-${desktop_name}}.desktop

	cat <<-EOF > "${desktop}"
	[Desktop Entry]
	Version=1.0
	Name=${name}
	Type=Application
	Comment=${DESCRIPTION}
	Exec=${exec}
	TryExec=${exec%% *}
	Icon=${icon}
	Categories=${type};
	EOF

	[[ ${path} ]] && echo "Path=${path}" >> "${desktop}"

	(
		# wrap the env here so that the 'insinto' call
		# doesn't corrupt the env of the caller
		insinto /usr/share/applications
		doins "${desktop}"
	)
}

# @FUNCTION: validate_desktop_entries
# @USAGE: [directories]
# @MAINTAINER:
# Carsten Lohrke <carlo@gentoo.org>
# @DESCRIPTION:
# Validate desktop entries using desktop-file-utils
validate_desktop_entries() {
	if [[ -x /usr/bin/desktop-file-validate ]] ; then
		einfo "Checking desktop entry validity"
		local directories=""
		for d in /usr/share/applications $@ ; do
			[[ -d ${D}${d} ]] && directories="${directories} ${D}${d}"
		done
		if [[ -n ${directories} ]] ; then
			for FILE in $(find ${directories} -name "*\.desktop" \
							-not -path '*.hidden*' | sort -u 2>/dev/null)
			do
				local temp=$(desktop-file-validate ${FILE} | grep -v "warning:" | \
								sed -e "s|error: ||" -e "s|${FILE}:|--|g" )
				[[ -n $temp ]] && elog ${temp/--/${FILE/${D}/}:}
			done
		fi
		echo ""
	else
		einfo "Passing desktop entry validity check. Install dev-util/desktop-file-utils, if you want to help to improve Gentoo."
	fi
}

# @FUNCTION: make_session_desktop
# @USAGE: <title> <command>
# @DESCRIPTION:
# Make a GDM/KDM Session file.  The title is the file to execute to start the
# Window Manager.  The command is the name of the Window Manager.
make_session_desktop() {
	[[ -z $1 ]] && eerror "make_session_desktop: You must specify the title" && return 1
	[[ -z $2 ]] && eerror "make_session_desktop: You must specify the command" && return 1

	local title=$1
	local command=$2
	local desktop=${T}/${wm}.desktop

	cat <<-EOF > "${desktop}"
	[Desktop Entry]
	Name=${title}
	Comment=This session logs you into ${title}
	Exec=${command}
	TryExec=${command}
	Type=Application
	EOF

	(
	# wrap the env here so that the 'insinto' call
	# doesn't corrupt the env of the caller
	insinto /usr/share/xsessions
	doins "${desktop}"
	)
}

# @FUNCTION: domenu
# @USAGE: <menus>
# @DESCRIPTION:
# Install the list of .desktop menu files into the appropriate directory
# (/usr/share/applications).
domenu() {
	(
	# wrap the env here so that the 'insinto' call
	# doesn't corrupt the env of the caller
	local i j ret=0
	insinto /usr/share/applications
	for i in "$@" ; do
		if [[ -f ${i} ]] ; then
			doins "${i}"
			((ret+=$?))
		elif [[ -d ${i} ]] ; then
			for j in "${i}"/*.desktop ; do
				doins "${j}"
				((ret+=$?))
			done
		else
			((++ret))
		fi
	done
	exit ${ret}
	)
}

# @FUNCTION: newmenu
# @USAGE: <menu> <newname>
# @DESCRIPTION:
# Like all other new* functions, install the specified menu as newname.
newmenu() {
	(
	# wrap the env here so that the 'insinto' call
	# doesn't corrupt the env of the caller
	insinto /usr/share/applications
	newins "$@"
	)
}

# @FUNCTION: doicon
# @USAGE: <list of icons>
# @DESCRIPTION:
# Install the list of icons into the icon directory (/usr/share/pixmaps).
# This is useful in conjunction with creating desktop/menu files.
doicon() {
	(
	# wrap the env here so that the 'insinto' call
	# doesn't corrupt the env of the caller
	local i j ret
	insinto /usr/share/pixmaps
	for i in "$@" ; do
		if [[ -f ${i} ]] ; then
			doins "${i}"
			((ret+=$?))
		elif [[ -d ${i} ]] ; then
			for j in "${i}"/*.png ; do
				doins "${j}"
				((ret+=$?))
			done
		else
			((++ret))
		fi
	done
	exit ${ret}
	)
}

# @FUNCTION: newicon
# @USAGE: <icon> <newname>
# @DESCRIPTION:
# Like all other new* functions, install the specified icon as newname.
newicon() {
	(
	# wrap the env here so that the 'insinto' call
	# doesn't corrupt the env of the caller
	insinto /usr/share/pixmaps
	newins "$@"
	)
}

# for internal use only (unpack_pdv and unpack_makeself)
find_unpackable_file() {
	local src=$1
	if [[ -z ${src} ]] ; then
		src=${DISTDIR}/${A}
	else
		if [[ -e ${DISTDIR}/${src} ]] ; then
			src=${DISTDIR}/${src}
		elif [[ -e ${PWD}/${src} ]] ; then
			src=${PWD}/${src}
		elif [[ -e ${src} ]] ; then
			src=${src}
		fi
	fi
	[[ ! -e ${src} ]] && return 1
	echo "${src}"
}

# @FUNCTION: unpack_pdv
# @USAGE: <file to unpack> <size of off_t>
# @DESCRIPTION:
# Unpack those pesky pdv generated files ...
# They're self-unpacking programs with the binary package stuffed in
# the middle of the archive.  Valve seems to use it a lot ... too bad
# it seems to like to segfault a lot :(.  So lets take it apart ourselves.
#
# You have to specify the off_t size ... I have no idea how to extract that
# information out of the binary executable myself.  Basically you pass in
# the size of the off_t type (in bytes) on the machine that built the pdv
# archive.
#
# One way to determine this is by running the following commands:
#
# @CODE
# 	strings <pdv archive> | grep lseek
# 	strace -elseek <pdv archive>
# @CODE
#
# Basically look for the first lseek command (we do the strings/grep because
# sometimes the function call is _llseek or something) and steal the 2nd
# parameter.  Here is an example:
#
# @CODE
# 	vapier@vapier 0 pdv_unpack # strings hldsupdatetool.bin | grep lseek
# 	lseek
# 	vapier@vapier 0 pdv_unpack # strace -elseek ./hldsupdatetool.bin
# 	lseek(3, -4, SEEK_END)					= 2981250
# @CODE
#
# Thus we would pass in the value of '4' as the second parameter.
unpack_pdv() {
	local src=$(find_unpackable_file "$1")
	local sizeoff_t=$2

	[[ -z ${src} ]] && die "Could not locate source for '$1'"
	[[ -z ${sizeoff_t} ]] && die "No idea what off_t size was used for this pdv :("

	local shrtsrc=$(basename "${src}")
	echo ">>> Unpacking ${shrtsrc} to ${PWD}"
	local metaskip=$(tail -c ${sizeoff_t} "${src}" | hexdump -e \"%i\")
	local tailskip=$(tail -c $((${sizeoff_t}*2)) "${src}" | head -c ${sizeoff_t} | hexdump -e \"%i\")

	# grab metadata for debug reasons
	local metafile=$(emktemp)
	tail -c +$((${metaskip}+1)) "${src}" > "${metafile}"

	# rip out the final file name from the metadata
	local datafile=$(tail -c +$((${metaskip}+1)) "${src}" | strings | head -n 1)
	datafile=$(basename "${datafile}")

	# now lets uncompress/untar the file if need be
	local tmpfile=$(emktemp)
	tail -c +$((${tailskip}+1)) ${src} 2>/dev/null | head -c 512 > ${tmpfile}

	local iscompressed=$(file -b "${tmpfile}")
	if [[ ${iscompressed:0:8} == "compress" ]] ; then
		iscompressed=1
		mv ${tmpfile}{,.Z}
		gunzip ${tmpfile}
	else
		iscompressed=0
	fi
	local istar=$(file -b "${tmpfile}")
	if [[ ${istar:0:9} == "POSIX tar" ]] ; then
		istar=1
	else
		istar=0
	fi

	#for some reason gzip dies with this ... dd cant provide buffer fast enough ?
	#dd if=${src} ibs=${metaskip} count=1 \
	#	| dd ibs=${tailskip} skip=1 \
	#	| gzip -dc \
	#	> ${datafile}
	if [ ${iscompressed} -eq 1 ] ; then
		if [ ${istar} -eq 1 ] ; then
			tail -c +$((${tailskip}+1)) ${src} 2>/dev/null \
				| head -c $((${metaskip}-${tailskip})) \
				| tar -xzf -
		else
			tail -c +$((${tailskip}+1)) ${src} 2>/dev/null \
				| head -c $((${metaskip}-${tailskip})) \
				| gzip -dc \
				> ${datafile}
		fi
	else
		if [ ${istar} -eq 1 ] ; then
			tail -c +$((${tailskip}+1)) ${src} 2>/dev/null \
				| head -c $((${metaskip}-${tailskip})) \
				| tar --no-same-owner -xf -
		else
			tail -c +$((${tailskip}+1)) ${src} 2>/dev/null \
				| head -c $((${metaskip}-${tailskip})) \
				> ${datafile}
		fi
	fi
	true
	#[ -s "${datafile}" ] || die "failure unpacking pdv ('${metaskip}' '${tailskip}' '${datafile}')"
	#assert "failure unpacking pdv ('${metaskip}' '${tailskip}' '${datafile}')"
}

# @FUNCTION: unpack_makeself
# @USAGE: [file to unpack] [offset] [tail|dd]
# @DESCRIPTION:
# Unpack those pesky makeself generated files ...
# They're shell scripts with the binary package tagged onto
# the end of the archive.  Loki utilized the format as does
# many other game companies.
#
# If the file is not specified, then ${A} is used.  If the
# offset is not specified then we will attempt to extract
# the proper offset from the script itself.
unpack_makeself() {
	local src_input=${1:-${A}}
	local src=$(find_unpackable_file "${src_input}")
	local skip=$2
	local exe=$3

	[[ -z ${src} ]] && die "Could not locate source for '${src_input}'"

	local shrtsrc=$(basename "${src}")
	echo ">>> Unpacking ${shrtsrc} to ${PWD}"
	if [[ -z ${skip} ]] ; then
		local ver=$(grep -a '#.*Makeself' "${src}" | awk '{print $NF}')
		local skip=0
		exe=tail
		case ${ver} in
			1.5.*|1.6.0-nv)	# tested 1.5.{3,4,5} ... guessing 1.5.x series is same
				skip=$(grep -a ^skip= "${src}" | cut -d= -f2)
				;;
			2.0|2.0.1)
				skip=$(grep -a ^$'\t'tail "${src}" | awk '{print $2}' | cut -b2-)
				;;
			2.1.1)
				skip=$(grep -a ^offset= "${src}" | awk '{print $2}' | cut -b2-)
				let skip="skip + 1"
				;;
			2.1.2)
				skip=$(grep -a ^offset= "${src}" | awk '{print $3}' | head -n 1)
				let skip="skip + 1"
				;;
			2.1.3)
				skip=`grep -a ^offset= "${src}" | awk '{print $3}'`
				let skip="skip + 1"
				;;
			2.1.4|2.1.5)
				skip=$(grep -a offset=.*head.*wc "${src}" | awk '{print $3}' | head -n 1)
				skip=$(head -n ${skip} "${src}" | wc -c)
				exe="dd"
				;;
			*)
				eerror "I'm sorry, but I was unable to support the Makeself file."
				eerror "The version I detected was '${ver}'."
				eerror "Please file a bug about the file ${shrtsrc} at"
				eerror "http://bugs.gentoo.org/ so that support can be added."
				die "makeself version '${ver}' not supported"
				;;
		esac
		debug-print "Detected Makeself version ${ver} ... using ${skip} as offset"
	fi
	case ${exe} in
		tail)	exe="tail -n +${skip} '${src}'";;
		dd)		exe="dd ibs=${skip} skip=1 obs=1024 conv=sync if='${src}'";;
		*)		die "makeself cant handle exe '${exe}'"
	esac

	# lets grab the first few bytes of the file to figure out what kind of archive it is
	local tmpfile=$(emktemp)
	eval ${exe} 2>/dev/null | head -c 512 > "${tmpfile}"
	local filetype=$(file -b "${tmpfile}")
	case ${filetype} in
		*tar\ archive*)
			eval ${exe} | tar --no-same-owner -xf -
			;;
		bzip2*)
			eval ${exe} | bzip2 -dc | tar --no-same-owner -xf -
			;;
		gzip*)
			eval ${exe} | tar --no-same-owner -xzf -
			;;
		compress*)
			eval ${exe} | gunzip | tar --no-same-owner -xf -
			;;
		*)
			eerror "Unknown filetype \"${filetype}\" ?"
			false
			;;
	esac
	assert "failure unpacking (${filetype}) makeself ${shrtsrc} ('${ver}' +${skip})"
}

# @FUNCTION: check_license
# @USAGE: [license]
# @DESCRIPTION:
# Display a license for user to accept.  If no license is
# specified, then ${LICENSE} is used.
check_license() {
	local lic=$1
	if [ -z "${lic}" ] ; then
		lic="${PORTDIR}/licenses/${LICENSE}"
	else
		if [ -e "${PORTDIR}/licenses/${lic}" ] ; then
			lic="${PORTDIR}/licenses/${lic}"
		elif [ -e "${PWD}/${lic}" ] ; then
			lic="${PWD}/${lic}"
		elif [ -e "${lic}" ] ; then
			lic="${lic}"
		fi
	fi
	[ ! -f "${lic}" ] && die "Could not find requested license ${lic}"
	local l="`basename ${lic}`"

	# here is where we check for the licenses the user already
	# accepted ... if we don't find a match, we make the user accept
	local shopts=$-
	local alic
	set -o noglob #so that bash doesn't expand "*"
	for alic in ${ACCEPT_LICENSE} ; do
		if [[ ${alic} == ${l} ]]; then
			set +o noglob; set -${shopts} #reset old shell opts
			return 0
		fi
	done
	set +o noglob; set -$shopts #reset old shell opts

	local licmsg=$(emktemp)
	cat <<-EOF > ${licmsg}
	**********************************************************
	The following license outlines the terms of use of this
	package.  You MUST accept this license for installation to
	continue.  When you are done viewing, hit 'q'.	If you
	CTRL+C out of this, the install will not run!
	**********************************************************

	EOF
	cat ${lic} >> ${licmsg}
	${PAGER:-less} ${licmsg} || die "Could not execute pager (${PAGER}) to accept ${lic}"
	einfon "Do you accept the terms of this license (${l})? [yes/no] "
	read alic
	case ${alic} in
		yes|Yes|y|Y)
			return 0
			;;
		*)
			echo;echo;echo
			eerror "You MUST accept the license to continue!  Exiting!"
			die "Failed to accept license"
			;;
	esac
}

# @FUNCTION: cdrom_get_cds
# @USAGE: <file on cd1> [file on cd2] [file on cd3] [...]
# @DESCRIPTION:
# Aquire cd(s) for those lovely cd-based emerges.  Yes, this violates
# the whole 'non-interactive' policy, but damnit I want CD support !
#
# With these cdrom functions we handle all the user interaction and
# standardize everything.  All you have to do is call cdrom_get_cds()
# and when the function returns, you can assume that the cd has been
# found at CDROM_ROOT.
#
# The function will attempt to locate a cd based upon a file that is on
# the cd.  The more files you give this function, the more cds
# the cdrom functions will handle.
#
# Normally the cdrom functions will refer to the cds as 'cd #1', 'cd #2',
# etc...  If you want to give the cds better names, then just export
# the appropriate CDROM_NAME variable before calling cdrom_get_cds().
# Use CDROM_NAME for one cd, or CDROM_NAME_# for multiple cds.  You can
# also use the CDROM_NAME_SET bash array.
#
# For those multi cd ebuilds, see the cdrom_load_next_cd() function.
cdrom_get_cds() {
	# first we figure out how many cds we're dealing with by
	# the # of files they gave us
	local cdcnt=0
	local f=
	for f in "$@" ; do
		((++cdcnt))
		export CDROM_CHECK_${cdcnt}="$f"
	done
	export CDROM_TOTAL_CDS=${cdcnt}
	export CDROM_CURRENT_CD=1

	# now we see if the user gave use CD_ROOT ...
	# if they did, let's just believe them that it's correct
	if [[ -n ${CD_ROOT}${CD_ROOT_1} ]] ; then
		local var=
		cdcnt=0
		while [[ ${cdcnt} -lt ${CDROM_TOTAL_CDS} ]] ; do
			((++cdcnt))
			var="CD_ROOT_${cdcnt}"
			[[ -z ${!var} ]] && var="CD_ROOT"
			if [[ -z ${!var} ]] ; then
				eerror "You must either use just the CD_ROOT"
				eerror "or specify ALL the CD_ROOT_X variables."
				eerror "In this case, you will need ${CDROM_TOTAL_CDS} CD_ROOT_X variables."
				die "could not locate CD_ROOT_${cdcnt}"
			fi
		done
		export CDROM_ROOT=${CD_ROOT_1:-${CD_ROOT}}
		einfo "Found CD #${CDROM_CURRENT_CD} root at ${CDROM_ROOT}"
		export CDROM_SET=-1
		for f in ${CDROM_CHECK_1//:/ } ; do
			((++CDROM_SET))
			[[ -e ${CD_ROOT}/${f} ]] && break
		done
		export CDROM_MATCH=${f}
		return
	fi

	# User didn't help us out so lets make sure they know they can
	# simplify the whole process ...
	if [[ ${CDROM_TOTAL_CDS} -eq 1 ]] ; then
		einfo "This ebuild will need the ${CDROM_NAME:-cdrom for ${PN}}"
		echo
		einfo "If you do not have the CD, but have the data files"
		einfo "mounted somewhere on your filesystem, just export"
		einfo "the variable CD_ROOT so that it points to the"
		einfo "directory containing the files."
		echo
		einfo "For example:"
		einfo "export CD_ROOT=/mnt/cdrom"
		echo
	else
		if [[ -n ${CDROM_NAME_SET} ]] ; then
			# Translate the CDROM_NAME_SET array into CDROM_NAME_#
			cdcnt=0
			while [[ ${cdcnt} -lt ${CDROM_TOTAL_CDS} ]] ; do
				((++cdcnt))
				export CDROM_NAME_${cdcnt}="${CDROM_NAME_SET[$((${cdcnt}-1))]}"
			done
		fi

		einfo "This package will need access to ${CDROM_TOTAL_CDS} cds."
		cdcnt=0
		while [[ ${cdcnt} -lt ${CDROM_TOTAL_CDS} ]] ; do
			((++cdcnt))
			var="CDROM_NAME_${cdcnt}"
			[[ ! -z ${!var} ]] && einfo " CD ${cdcnt}: ${!var}"
		done
		echo
		einfo "If you do not have the CDs, but have the data files"
		einfo "mounted somewhere on your filesystem, just export"
		einfo "the following variables so they point to the right place:"
		einfon ""
		cdcnt=0
		while [[ ${cdcnt} -lt ${CDROM_TOTAL_CDS} ]] ; do
			((++cdcnt))
			echo -n " CD_ROOT_${cdcnt}"
		done
		echo
		einfo "Or, if you have all the files in the same place, or"
		einfo "you only have one cdrom, you can export CD_ROOT"
		einfo "and that place will be used as the same data source"
		einfo "for all the CDs."
		echo
		einfo "For example:"
		einfo "export CD_ROOT_1=/mnt/cdrom"
		echo
	fi

	export CDROM_SET=""
	export CDROM_CURRENT_CD=0
	cdrom_load_next_cd
}

# @FUNCTION: cdrom_load_next_cd
# @DESCRIPTION:
# Some packages are so big they come on multiple CDs.  When you're done reading
# files off a CD and want access to the next one, just call this function.
# Again, all the messy details of user interaction are taken care of for you.
# Once this returns, just read the variable CDROM_ROOT for the location of the
# mounted CD.  Note that you can only go forward in the CD list, so make sure
# you only call this function when you're done using the current CD.
cdrom_load_next_cd() {
	local var
	((++CDROM_CURRENT_CD))

	unset CDROM_ROOT
	var=CD_ROOT_${CDROM_CURRENT_CD}
	[[ -z ${!var} ]] && var="CD_ROOT"
	if [[ -z ${!var} ]] ; then
		var="CDROM_CHECK_${CDROM_CURRENT_CD}"
		_cdrom_locate_file_on_cd ${!var}
	else
		export CDROM_ROOT=${!var}
	fi

	einfo "Found CD #${CDROM_CURRENT_CD} root at ${CDROM_ROOT}"
}

# this is used internally by the cdrom_get_cds() and cdrom_load_next_cd()
# functions.  this should *never* be called from an ebuild.
# all it does is try to locate a give file on a cd ... if the cd isn't
# found, then a message asking for the user to insert the cdrom will be
# displayed and we'll hang out here until:
# (1) the file is found on a mounted cdrom
# (2) the user hits CTRL+C
_cdrom_locate_file_on_cd() {
	local mline=""
	local showedmsg=0 showjolietmsg=0

	while [[ -z ${CDROM_ROOT} ]] ; do
		local i=0
		local -a cdset=(${*//:/ })
		if [[ -n ${CDROM_SET} ]] ; then
			cdset=(${cdset[${CDROM_SET}]})
		fi

		while [[ -n ${cdset[${i}]} ]] ; do
			local dir=$(dirname ${cdset[${i}]})
			local file=$(basename ${cdset[${i}]})

			local point= node= fs= foo=
			while read point node fs foo ; do
				[[ " cd9660 iso9660 udf " != *" ${fs} "* ]] && \
					! [[ ${fs} == "subfs" && ",${opts}," == *",fs=cdfss,"* ]] \
					&& continue
				point=${point//\040/ }
				[[ ! -d ${point}/${dir} ]] && continue
				[[ -z $(find "${point}/${dir}" -maxdepth 1 -iname "${file}") ]] && continue
				export CDROM_ROOT=${point}
				export CDROM_SET=${i}
				export CDROM_MATCH=${cdset[${i}]}
				return
			done <<< "$(get_mounts)"

			((++i))
		done

		echo
		if [[ ${showedmsg} -eq 0 ]] ; then
			if [[ ${CDROM_TOTAL_CDS} -eq 1 ]] ; then
				if [[ -z ${CDROM_NAME} ]] ; then
					einfo "Please insert+mount the cdrom for ${PN} now !"
				else
					einfo "Please insert+mount the ${CDROM_NAME} cdrom now !"
				fi
			else
				if [[ -z ${CDROM_NAME_1} ]] ; then
					einfo "Please insert+mount cd #${CDROM_CURRENT_CD} for ${PN} now !"
				else
					local var="CDROM_NAME_${CDROM_CURRENT_CD}"
					einfo "Please insert+mount the ${!var} cdrom now !"
				fi
			fi
			showedmsg=1
		fi
		einfo "Press return to scan for the cd again"
		einfo "or hit CTRL+C to abort the emerge."
		echo
		if [[ ${showjolietmsg} -eq 0 ]] ; then
			showjolietmsg=1
		else
			ewarn "If you are having trouble with the detection"
			ewarn "of your CD, it is possible that you do not have"
			ewarn "Joliet support enabled in your kernel.  Please"
			ewarn "check that CONFIG_JOLIET is enabled in your kernel."
			ebeep 5
		fi
		read || die "something is screwed with your system"
	done
}

# @FUNCTION: strip-linguas
# @USAGE: [<allow LINGUAS>|<-i|-u> <directories of .po files>]
# @DESCRIPTION:
# Make sure that LINGUAS only contains languages that
# a package can support.  The first form allows you to
# specify a list of LINGUAS.  The -i builds a list of po
# files found in all the directories and uses the
# intersection of the lists.  The -u builds a list of po
# files found in all the directories and uses the union
# of the lists.
strip-linguas() {
	local ls newls nols
	if [[ $1 == "-i" ]] || [[ $1 == "-u" ]] ; then
		local op=$1; shift
		ls=$(find "$1" -name '*.po' -exec basename {} .po \;); shift
		local d f
		for d in "$@" ; do
			if [[ ${op} == "-u" ]] ; then
				newls=${ls}
			else
				newls=""
			fi
			for f in $(find "$d" -name '*.po' -exec basename {} .po \;) ; do
				if [[ ${op} == "-i" ]] ; then
					hasq ${f} ${ls} && newls="${newls} ${f}"
				else
					hasq ${f} ${ls} || newls="${newls} ${f}"
				fi
			done
			ls=${newls}
		done
	else
		ls="$@"
	fi

	nols=""
	newls=""
	for f in ${LINGUAS} ; do
		if hasq ${f} ${ls} ; then
			newls="${newls} ${f}"
		else
			nols="${nols} ${f}"
		fi
	done
	[[ -n ${nols} ]] \
		&& ewarn "Sorry, but ${PN} does not support the LINGUAs:" ${nols}
	export LINGUAS=${newls:1}
}

# @FUNCTION: preserve_old_lib
# @USAGE: <libs to preserve> [more libs]
# @DESCRIPTION:
# These functions are useful when a lib in your package changes ABI SONAME.
# An example might be from libogg.so.0 to libogg.so.1.  Removing libogg.so.0
# would break packages that link against it.  Most people get around this
# by using the portage SLOT mechanism, but that is not always a relevant
# solution, so instead you can call this from pkg_preinst.  See also the
# preserve_old_lib_notify function.
preserve_old_lib() {
	if [[ ${EBUILD_PHASE} != "preinst" ]] ; then
		eerror "preserve_old_lib() must be called from pkg_preinst() only"
		die "Invalid preserve_old_lib() usage"
	fi
	[[ -z $1 ]] && die "Usage: preserve_old_lib <library to preserve> [more libraries to preserve]"

	# let portage worry about it
	has preserve-libs ${FEATURES} && return 0

	local lib dir
	for lib in "$@" ; do
		[[ -e ${ROOT}/${lib} ]] || continue
		dir=${lib%/*}
		dodir ${dir} || die "dodir ${dir} failed"
		cp "${ROOT}"/${lib} "${D}"/${lib} || die "cp ${lib} failed"
		touch "${D}"/${lib}
	done
}

# @FUNCTION: preserve_old_lib_notify
# @USAGE: <libs to notify> [more libs]
# @DESCRIPTION:
# Spit helpful messages about the libraries preserved by preserve_old_lib.
preserve_old_lib_notify() {
	if [[ ${EBUILD_PHASE} != "postinst" ]] ; then
		eerror "preserve_old_lib_notify() must be called from pkg_postinst() only"
		die "Invalid preserve_old_lib_notify() usage"
	fi

	# let portage worry about it
	has preserve-libs ${FEATURES} && return 0

	local lib notice=0
	for lib in "$@" ; do
		[[ -e ${ROOT}/${lib} ]] || continue
		if [[ ${notice} -eq 0 ]] ; then
			notice=1
			ewarn "Old versions of installed libraries were detected on your system."
			ewarn "In order to avoid breaking packages that depend on these old libs,"
			ewarn "the libraries are not being removed.  You need to run revdep-rebuild"
			ewarn "in order to remove these old dependencies.  If you do not have this"
			ewarn "helper program, simply emerge the 'gentoolkit' package."
			ewarn
		fi
		ewarn "  # revdep-rebuild --library ${lib##*/}"
	done
	if [[ ${notice} -eq 1 ]] ; then
		ewarn
		ewarn "Once you've finished running revdep-rebuild, it should be safe to"
		ewarn "delete the old libraries."
	fi
}

# @FUNCTION: built_with_use
# @USAGE: [--hidden] [--missing <action>] [-a|-o] <DEPEND ATOM> <List of USE flags>
# @DESCRIPTION:
# A temporary hack until portage properly supports DEPENDing on USE
# flags being enabled in packages.  This will check to see if the specified
# DEPEND atom was built with the specified list of USE flags.  The
# --missing option controls the behavior if called on a package that does
# not actually support the defined USE flags (aka listed in IUSE).
# The default is to abort (call die).  The -a and -o flags control
# the requirements of the USE flags.  They correspond to "and" and "or"
# logic.  So the -a flag means all listed USE flags must be enabled
# while the -o flag means at least one of the listed fIUSE flags must be
# enabled.  The --hidden option is really for internal use only as it
# means the USE flag we're checking is hidden expanded, so it won't be found
# in IUSE like normal USE flags.
#
# Remember that this function isn't terribly intelligent so order of optional
# flags matter.
built_with_use() {
	local hidden="no"
	if [[ $1 == "--hidden" ]] ; then
		hidden="yes"
		shift
	fi

	local missing_action="die"
	if [[ $1 == "--missing" ]] ; then
		missing_action=$2
		shift ; shift
		case ${missing_action} in
			true|false|die) ;;
			*) die "unknown action '${missing_action}'";;
		esac
	fi

	local opt=$1
	[[ ${opt:0:1} = "-" ]] && shift || opt="-a"

	local PKG=$(best_version $1)
	[[ -z ${PKG} ]] && die "Unable to resolve $1 to an installed package"
	shift

	local USEFILE=${ROOT}/var/db/pkg/${PKG}/USE
	local IUSEFILE=${ROOT}/var/db/pkg/${PKG}/IUSE

	# if the IUSE file doesn't exist, the read will error out, we need to handle
	# this gracefully
	if [[ ! -e ${USEFILE} ]] || [[ ! -e ${IUSEFILE} && ${hidden} == "no" ]] ; then
		case ${missing_action} in
			true)	return 0;;
			false)	return 1;;
			die)	die "Unable to determine what USE flags $PKG was built with";;
		esac
	fi

	if [[ ${hidden} == "no" ]] ; then
		local IUSE_BUILT=$(<${IUSEFILE})
		# Don't check USE_EXPAND #147237
		local expand
		for expand in $(echo ${USE_EXPAND} | tr '[:upper:]' '[:lower:]') ; do
			if [[ $1 == ${expand}_* ]] ; then
				expand=""
				break
			fi
		done
		if [[ -n ${expand} ]] ; then
			if ! has $1 ${IUSE_BUILT} ; then
				case ${missing_action} in
					true)  return 0;;
					false) return 1;;
					die)   die "$PKG does not actually support the $1 USE flag!";;
				esac
			fi
		fi
	fi

	local USE_BUILT=$(<${USEFILE})
	while [[ $# -gt 0 ]] ; do
		if [[ ${opt} = "-o" ]] ; then
			has $1 ${USE_BUILT} && return 0
		else
			has $1 ${USE_BUILT} || return 1
		fi
		shift
	done
	[[ ${opt} = "-a" ]]
}

# @FUNCTION: epunt_cxx
# @USAGE: [dir to scan]
# @DESCRIPTION:
# Many configure scripts wrongly bail when a C++ compiler could not be
# detected.  If dir is not specified, then it defaults to ${S}.
#
# http://bugs.gentoo.org/73450
epunt_cxx() {
	local dir=$1
	[[ -z ${dir} ]] && dir=${S}
	ebegin "Removing useless C++ checks"
	local f
	find "${dir}" -name configure | while read f ; do
		patch --no-backup-if-mismatch -p0 "${f}" "${PORTDIR}/eclass/ELT-patches/nocxx/nocxx.patch" > /dev/null
	done
	eend 0
}

# @FUNCTION: make_wrapper
# @USAGE: <wrapper> <target> [chdir] [libpaths] [installpath]
# @DESCRIPTION:
# Create a shell wrapper script named wrapper in installpath
# (defaults to the bindir) to execute target (default of wrapper) by
# first optionally setting LD_LIBRARY_PATH to the colon-delimited
# libpaths followed by optionally changing directory to chdir.
make_wrapper() {
	local wrapper=$1 bin=$2 chdir=$3 libdir=$4 path=$5
	local tmpwrapper=$(emktemp)
	# We don't want to quote ${bin} so that people can pass complex
	# things as $bin ... "./someprog --args"
	cat << EOF > "${tmpwrapper}"
#!/bin/sh
cd "${chdir:-.}"
if [ -n "${libdir}" ] ; then
	if [ "\${LD_LIBRARY_PATH+set}" = "set" ] ; then
		export LD_LIBRARY_PATH="\${LD_LIBRARY_PATH}:${libdir}"
	else
		export LD_LIBRARY_PATH="${libdir}"
	fi
fi
exec ${bin} "\$@"
EOF
	chmod go+rx "${tmpwrapper}"
	if [[ -n ${path} ]] ; then
		(
		exeinto "${path}"
		newexe "${tmpwrapper}" "${wrapper}"
		) || die
	else
		newbin "${tmpwrapper}" "${wrapper}" || die
	fi
}