From 8710b6501b0c3886d4884a0abfc726255a5712c9 Mon Sep 17 00:00:00 2001
From: Jun Wu <quark@lihdd.net>
Date: Mon, 28 Apr 2014 20:36:08 +0800
Subject: [PATCH] Better "exec 3>&1" comment

"Copy stdout to fd 3" is confusing. Explain the intention behind `exec 3>&1`.

Change-Id: Id19434121876e65a14c709beac26b9daf4a36a0a
---
 stack.sh | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/stack.sh b/stack.sh
index 4a8cb90d61..19d47d64ae 100755
--- a/stack.sh
+++ b/stack.sh
@@ -543,10 +543,11 @@ if [[ -n "$LOGFILE" ]]; then
 
     # Redirect output according to config
 
-    # Copy stdout to fd 3
+    # Set fd 3 to a copy of stdout. So we can set fd 1 without losing
+    # stdout later.
     exec 3>&1
     if [[ "$VERBOSE" == "True" ]]; then
-        # Redirect stdout/stderr to tee to write the log file
+        # Set fd 1 and 2 to write the log file
         exec 1> >( awk -v logfile=${LOGFILE} '
                 /((set \+o$)|xtrace)/ { next }
                 {
@@ -559,7 +560,7 @@ if [[ -n "$LOGFILE" ]]; then
                     print
                     fflush("")
                 }' ) 2>&1
-        # Set up a second fd for output
+        # Set fd 6 to summary log file
         exec 6> >( tee "${SUMFILE}" )
     else
         # Set fd 1 and 2 to primary logfile
@@ -574,7 +575,8 @@ if [[ -n "$LOGFILE" ]]; then
     ln -sf $SUMFILE $LOGDIR/$LOGFILENAME.summary
 else
     # Set up output redirection without log files
-    # Copy stdout to fd 3
+    # Set fd 3 to a copy of stdout. So we can set fd 1 without losing
+    # stdout later.
     exec 3>&1
     if [[ "$VERBOSE" != "True" ]]; then
         # Throw away stdout and stderr