From 0897d999e63be4e2e6e5c385b72a02dd649086ee Mon Sep 17 00:00:00 2001
From: sin <sin@2f30.org>
Date: Thu, 17 Apr 2014 16:38:31 +0100
Subject: [PATCH] Implement streplace()

Restore variable as early as possible and in error conditions
---
 sysctl.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/sysctl.c b/sysctl.c
index e9a3898..6a764e5 100644
--- a/sysctl.c
+++ b/sysctl.c
@@ -7,6 +7,16 @@
 #include <unistd.h>
 #include "util.h"
 
+static void
+streplace(char *s, int a, int b)
+{
+	char *p;
+
+	for (p = s; *p; p++)
+		if (*p == a)
+			*p = b;
+}
+
 static int
 getsysctl(char *variable, char **value)
 {
@@ -17,13 +27,15 @@ getsysctl(char *variable, char **value)
 	ssize_t n;
 	size_t sz, i;
 
-	for (p = variable; *p; p++)
-		if (*p == '.')
-			*p = '/';
+	streplace(variable, '.', '/');
 
 	strlcpy(path, "/proc/sys/", sizeof(path));
-	if (strlcat(path, variable, sizeof(path)) >= sizeof(path))
+	if (strlcat(path, variable, sizeof(path)) >= sizeof(path)) {
+		streplace(variable, '/', '.');
 		return -1;
+	}
+
+	streplace(variable, '/', '.');
 
 	fd = open(path, O_RDONLY);
 	if (fd < 0)
@@ -59,10 +71,6 @@ getsysctl(char *variable, char **value)
 	if (p)
 		*p = '\0';
 
-	for (p = variable; *p; p++)
-		if (*p == '/')
-			*p = '.';
-
 	*value = buf;
 
 	close(fd);