[RFC/PATCH 3/4] test-lib: provide lazy TIME_COMMAND prereq

[Michael J Gruber <git@drmicha.warpmail.net>]

Some test want to use the time command (not the shell builtin) and test
for its availability at /usr/bin/time.

Provide a lazy prereq TIME_COMMAND which tests for /usr/bin/time and
/bin/time. If any is found, set TEST_COMMAND_PATH to the first match.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
---
Rather than iterating over 2 or more hardcoded paths, one could use
"test -P time" or allow a make variable TIME_COMMAND_PATH whose
executability is checked by the prereq. I really don't know what's best.

 t/test-lib.sh | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 489bc80..7977c15 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -738,6 +738,13 @@ test_lazy_prereq UTF8_NFD_TO_NFC '
 	esac
 '
 
+test_lazy_prereq TIME_COMMAND '
+	for command in /usr/bin/time /bin/time
+	do
+		test -x "$command" && break
+	done && TIME_COMMAND_PATH="$command"
+'
+
 # When the tests are run as root, permission tests will report that
 # things are writable when they shouldn't be.
 test -w / || test_set_prereq SANITY
-- 
1.8.0.rc2.304.g9f3ac5c