all repos — slstatus @ 422cadfd5ffd78ae1b8fdf15734e03bd0333b26e

my build of slstatus (tools.suckless.org/slstatus/) 

Implement esnprintf() and make formatted calls more efficient

Within the components, snprintf() was unchecked and had inefficient
calls in some places.
We implement esnprintf() that does all the dirty laundry for us
and use it exclusively now.
Laslo Hunhold dev@frign.de
Sat, 19 May 2018 19:33:04 +0200
commit

422cadfd5ffd78ae1b8fdf15734e03bd0333b26e

parent

f31b113e7e85bf7057cb88a70d88c5ce9325e208

6 files changed, 72 insertions(+), 23 deletions(-)

jump to
M components/battery.c → components/battery.c 
@@ -14,9 +14,16 @@ {
 		int perc;
 		char path[PATH_MAX];
 
-		snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-		         bat, "/capacity");
-		return (pscanf(path, "%d", &perc) == 1) ? bprintf("%d", perc) : NULL;
+		if (esnprintf(path, sizeof(path),
+		              "/sys/class/power_supply/%s/capacity",
+		              bat) < 0) {
+			return NULL;
+		}
+		if (pscanf(path, "%d", &perc) != 1) {
+			return NULL;
+		}
+
+		return bprintf("%d", perc);
 	}
 
 	const char *

@@ -32,8 +39,11 @@ };
 		size_t i;
 		char path[PATH_MAX], state[12];
 
-		snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-		         bat, "/status");
+		if (esnprintf(path, sizeof(path),
+		              "/sys/class/power_supply/%s/status",
+		              bat) < 0) {
+			return NULL;
+		}
 		if (pscanf(path, "%12s", state) != 1) {
 			return NULL;
 		}

@@ -53,20 +63,29 @@ int charge_now, current_now, m, h;
 		float timeleft;
 		char path[PATH_MAX], state[12];
 
-		snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-		         bat, "/status");
+		if (esnprintf(path, sizeof(path),
+		              "/sys/class/power_supply/%s/status",
+		              bat) < 0) {
+			return NULL;
+		}
 		if (pscanf(path, "%12s", state) != 1) {
 			return NULL;
 		}
 
 		if (!strcmp(state, "Discharging")) {
-			snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-					 bat, "/charge_now");
+			if (esnprintf(path, sizeof(path),
+                                      "/sys/class/power_supply/%s/charge_now",
+			              bat) < 0) {
+				return NULL;
+			}
 			if (pscanf(path, "%d", &charge_now) != 1) {
 				return NULL;
 			}
-			snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/",
-					 bat, "/current_now");
+			if (esnprintf(path, sizeof(path),
+			              "/sys/class/power_supply/%s/current_now",
+			              bat) < 0) {
+				return NULL;
+			}
 			if (pscanf(path, "%d", &current_now) != 1) {
 				return NULL;
 			}
M components/netspeeds.c → components/netspeeds.c 
@@ -17,8 +17,11 @@ char path[PATH_MAX];
 
 		oldrxbytes = rxbytes;
 
-		snprintf(path, sizeof(path),
-		         "/sys/class/net/%s/statistics/rx_bytes", interface);
+		if (esnprintf(path, sizeof(path),
+		              "/sys/class/net/%s/statistics/rx_bytes",
+		              interface) < 0) {
+			return NULL;
+		}
 		if (pscanf(path, "%llu", &rxbytes) != 1) {
 			return NULL;
 		}

@@ -37,8 +40,11 @@ char path[PATH_MAX];
 
 		oldtxbytes = txbytes;
 
-		snprintf(path, sizeof(path),
-		         "/sys/class/net/%s/statistics/tx_bytes", interface);
+		if (esnprintf(path, sizeof(path),
+		              "/sys/class/net/%s/statistics/tx_bytes",
+		              interface) < 0) {
+			return NULL;
+		}
 		if (pscanf(path, "%llu", &txbytes) != 1) {
 			return NULL;
 		}
M components/wifi.c → components/wifi.c 
@@ -23,8 +23,11 @@ char path[PATH_MAX];
 		char status[5];
 		FILE *fp;
 
-		snprintf(path, sizeof(path), "%s%s%s", "/sys/class/net/", iface,
-		         "/operstate");
+		if (esnprintf(path, sizeof(path),
+		              "/sys/class/net/%s/operstate",
+		              iface) < 0) {
+			return NULL;
+		}
 		if (!(fp = fopen(path, "r"))) {
 			warn("fopen '%s':", path);
 			return NULL;

@@ -69,7 +72,10 @@ struct iwreq wreq;
 
 		memset(&wreq, 0, sizeof(struct iwreq));
 		wreq.u.essid.length = IW_ESSID_MAX_SIZE+1;
-		snprintf(wreq.ifr_name, sizeof(wreq.ifr_name), "%s", iface);
+		if (esnprintf(wreq.ifr_name, sizeof(wreq.ifr_name),
+		              "%s", iface) < 0) {
+			return NULL;
+		}
 
 		if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 			warn("socket 'AF_INET':");
M slstatus.c → slstatus.c 
@@ -91,12 +91,8 @@ for (i = len = 0; i < LEN(args); i++) {
 			if (!(res = args[i].func(args[i].args))) {
 				res = unknown_str;
 			}
-			if ((ret = snprintf(status + len, sizeof(status) - len,
+			if ((ret = esnprintf(status + len, sizeof(status) - len,
 			                    args[i].fmt, res)) < 0) {
-				warn("snprintf:");
-				break;
-			} else if ((size_t)ret >= sizeof(status) - len) {
-				warn("snprintf: Output truncated");
 				break;
 			}
 			len += ret;
M util.c → util.c 
@@ -48,6 +48,27 @@ 
 	exit(1);
 }
 
+int
+esnprintf(char *str, size_t size, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, fmt);
+	ret = vsnprintf(str, size, fmt, ap);
+	va_end(ap);
+
+	if (ret < 0) {
+		warn("snprintf:");
+		return -1;
+	} else if ((size_t)ret >= size) {
+		warn("snprintf: Output truncated");
+		return -1;
+	}
+
+	return ret;
+}
+
 const char *
 bprintf(const char *fmt, ...)
 {
M util.h → util.h 
@@ -8,6 +8,7 @@ 
 void warn(const char *, ...);
 void die(const char *, ...);
 
+int esnprintf(char *str, size_t size, const char *fmt, ...);
 const char *bprintf(const char *fmt, ...);
 const char *fmt_scaled(size_t);
 int pscanf(const char *path, const char *fmt, ...);