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

[Michał Górny]

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