[PATCH v3 4/5] selftests: ftrace: Output only to console with "--logdir -"

[Masami Hiramatsu]

Output logs only to console if "-" is given to --logdir
option. In this case, ftracetest doesn't record any log
on the disk, and all logs immediately shown (including
all command logs.) Since there is no "tee" in the middle
of command and console, it outputs the log really soon.

This option is useful only when the console is logged.

Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
---
  Changes in v3:
   - Use [ ! -z "$VAR" ] instead of [ "$VAR" ].
---
 tools/testing/selftests/ftrace/ftracetest |   29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/ftrace/ftracetest 
b/tools/testing/selftests/ftrace/ftracetest
index 892ca4e..453f73d 100755
--- a/tools/testing/selftests/ftrace/ftracetest
+++ b/tools/testing/selftests/ftrace/ftracetest
@@ -19,6 +19,7 @@ echo "                -vvv       Alias of -v -v -v (Show all 
commands immediately)"
 echo "         --fail-unsupported Treat UNSUPPORTED as a failure"
 echo "         -d|--debug Debug mode (trace all shell commands)"
 echo "         -l|--logdir <dir> Save logs on the <dir>"
+echo "                     If <dir> is -, all logs output in console only"
 exit $1
 }
 
@@ -127,14 +128,20 @@ if [ -z "$TRACING_DIR" -o ! -d "$TRACING_DIR" ]; then
 fi
 
 # Preparing logs
-LOG_FILE=$LOG_DIR/ftracetest.log
-mkdir -p $LOG_DIR || errexit "Failed to make a log directory: $LOG_DIR"
-date > $LOG_FILE
+if [ "x$LOG_DIR" = "x-" ]; then
+  LOG_FILE=
+  date
+else
+  LOG_FILE=$LOG_DIR/ftracetest.log
+  mkdir -p $LOG_DIR || errexit "Failed to make a log directory: $LOG_DIR"
+  date > $LOG_FILE
+fi
+
 prlog() { # messages
-  echo "$@" | tee -a $LOG_FILE
+  [ -z "$LOG_FILE" ] && echo "$@" || echo "$@" | tee -a $LOG_FILE
 }
 catlog() { #file
-  cat $1 | tee -a $LOG_FILE
+  [ -z "$LOG_FILE" ] && cat $1 || cat $1 | tee -a $LOG_FILE
 }
 prlog "=== Ftrace unit tests ==="
 
@@ -255,12 +262,18 @@ __run_test() { # testfile
 # Run one test case
 run_test() { # testfile
   local testname=`basename $1`
-  local testlog=`mktemp $LOG_DIR/${testname}-log.XXXXXX`
+  if [ ! -z "$LOG_FILE" ] ; then
+    local testlog=`mktemp $LOG_DIR/${testname}-log.XXXXXX`
+  else
+    local testlog=`/proc/self/fd/1`
+  fi
   export TMPDIR=`mktemp -d /tmp/ftracetest-dir.XXXXXX`
   testcase $1
   echo "execute$INSTANCE: "$1 > $testlog
   SIG_RESULT=0
-  if [ $VERBOSE -ge 3 ]; then
+  if [ -z "$LOG_FILE" ]; then
+    __run_test $1 2>&1
+  elif [ $VERBOSE -ge 3 ]; then
     __run_test $1 | tee -a $testlog 2>&1
   elif [ $VERBOSE -eq 2 ]; then
     __run_test $1 2>> $testlog | tee -a $testlog
@@ -270,7 +283,7 @@ run_test() { # testfile
   eval_result $SIG_RESULT
   if [ $? -eq 0 ]; then
     # Remove test log if the test was done as it was expected.
-    [ $KEEP_LOG -eq 0 ] && rm $testlog
+    [ $KEEP_LOG -eq 0 -a ! -z "$LOG_FILE" ] && rm $testlog
   else
     [ $VERBOSE -eq 1 -o $VERBOSE -eq 2 ] && catlog $testlog
     TOTAL_RESULT=1