[gentoo-dev] [PATCH 2/8] Use bash redirection to run 'tee' rather than simple pipes.

["Michał Górny" <mgorny@gentoo.org>]

This allows us to spawn 'tee' as separate process while keeping
the function code executed in the main shell.
---
 gx86/eclass/multibuild.eclass | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/gx86/eclass/multibuild.eclass b/gx86/eclass/multibuild.eclass
index 716d34f..d42b8a7 100644
--- a/gx86/eclass/multibuild.eclass
+++ b/gx86/eclass/multibuild.eclass
@@ -108,18 +108,20 @@ multibuild_foreach() {
 		local MULTIBUILD_VARIANT=${v}
 		local MULTIBUILD_ID=${prev_id}${v}
 		local BUILD_DIR=${bdir%%/}-${v}
+		local log_fd
 
-		einfo "${v}: running ${@}" \
-			| tee -a "${T}/build-${MULTIBUILD_ID}.log"
+		# redirect_alloc_fd accepts files only. so we need to open
+		# a random file and then reuse the fd for logger process.
+		redirect_alloc_fd log_fd /dev/null
+		eval "exec ${log_fd}> "'>(exec tee -a "${T}/build-${MULTIBUILD_ID}.log")'
+
+		eval 'einfo "${v}: running ${@}" >&'${log_fd}' 2>&1'
 
 		# _multibuild_parallel() does redirection internally.
 		# this is a hidden API to avoid writing multilib_foreach twice.
-		if [[ ${1} == _multibuild_parallel ]]; then
-			"${@}"
-		else
-			"${@}" 2>&1 | tee -a "${T}/build-${MULTIBUILD_ID}.log"
-		fi
+		eval '"${@}" >&'${log_fd}' 2>&1'
 		lret=${?}
+		eval "exec ${log_fd}>&-"
 	done
 	[[ ${ret} -eq 0 && ${lret} -ne 0 ]] && ret=${lret}
 
@@ -145,8 +147,7 @@ multibuild_parallel_foreach() {
 	_multibuild_parallel() {
 		(
 			multijob_child_init
-			"${@}" 2>&1 | tee -a "${T}/build-${MULTIBUILD_ID}.log"
-			exit ${PIPESTATUS[0]}
+			"${@}"
 		) &
 		multijob_post_fork
 	}
-- 
1.8.1.4