sys-process/cronbase: fix non-POSIX shell code #595492

johu · Nov 15, 2016 · b11e8d8 · b11e8d8
1 parent aaaeea2
commit b11e8d8
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diff --git a/...process/cronbase/cronbase-0.3.7-r5.ebuild → ...process/cronbase/cronbase-0.3.7-r6.ebuild b/...process/cronbase/cronbase-0.3.7-r5.ebuild → ...process/cronbase/cronbase-0.3.7-r6.ebuild
diff --git a/sys-process/cronbase/files/run-crons-0.3.7 b/sys-process/cronbase/files/run-crons-0.3.7
@@ -56,7 +56,18 @@ grab_lock() {
 
 		# This is better than kill -0 because we can verify that it's really
 		# another run-crons process.
-		if diff -qs /proc/{${cronpid},$$}/cmdline > /dev/null 2>&1; then
+		# We have to send stderr to /dev/null for two reasons:
+		# - If the process disappears, the cmdline file might not exist.
+		# - The cmdline file contains NUL bytes, but bash-4.4+ warns when
+		#   you try to assign NUL bytes to variables.
+		# It'd be nice to not do it for a lot of code, but there's not easy
+		# alternative in shell code.  We could `cat | tr`, but that'd waste
+		# a bit more than just a simple cat.
+		if (
+			cmdline1=$(cat "/proc/${cronpid}/cmdline") || :
+			cmdline2=$(cat "/proc/$$/cmdline")
+			[ "${cmdline1}" = "${cmdline2}" ]
+		) 2>/dev/null ; then
 			# Whoa, another run-crons is really running.
 			return 1
 		fi