use a static buffer instead of dynamic memory

1 files changed, 200 insertions, 241 deletions

diff --git a/slstatus.c b/slstatus.c
index cb4798b..b592446 100644
--- a/slstatus.c
+++ b/slstatus.c
@@ -28,45 +28,45 @@
 #include "arg.h"
 
 struct arg {
-	char *(*func)();
+	const char *(*func)();
 	const char *fmt;
 	const char *args;
 };
 
-static char *smprintf(const char *fmt, ...);
-static char *battery_perc(const char *bat);
-static char *battery_power(const char *bat);
-static char *battery_state(const char *bat);
-static char *cpu_freq(void);
-static char *cpu_perc(void);
-static char *datetime(const char *fmt);
-static char *disk_free(const char *mnt);
-static char *disk_perc(const char *mnt);
-static char *disk_total(const char *mnt);
-static char *disk_used(const char *mnt);
-static char *entropy(void);
-static char *gid(void);
-static char *hostname(void);
-static char *ip(const char *iface);
-static char *kernel_release(void);
-static char *keyboard_indicators(void);
-static char *load_avg(void);
-static char *ram_free(void);
-static char *ram_perc(void);
-static char *ram_used(void);
-static char *ram_total(void);
-static char *run_command(const char *cmd);
-static char *swap_free(void);
-static char *swap_perc(void);
-static char *swap_used(void);
-static char *swap_total(void);
-static char *temp(const char *file);
-static char *uid(void);
-static char *uptime(void);
-static char *username(void);
-static char *vol_perc(const char *card);
-static char *wifi_perc(const char *iface);
-static char *wifi_essid(const char *iface);
+static const char *bprintf(const char *fmt, ...);
+static const char *battery_perc(const char *bat);
+static const char *battery_power(const char *bat);
+static const char *battery_state(const char *bat);
+static const char *cpu_freq(void);
+static const char *cpu_perc(void);
+static const char *datetime(const char *fmt);
+static const char *disk_free(const char *mnt);
+static const char *disk_perc(const char *mnt);
+static const char *disk_total(const char *mnt);
+static const char *disk_used(const char *mnt);
+static const char *entropy(void);
+static const char *gid(void);
+static const char *hostname(void);
+static const char *ip(const char *iface);
+static const char *kernel_release(void);
+static const char *keyboard_indicators(void);
+static const char *load_avg(void);
+static const char *ram_free(void);
+static const char *ram_perc(void);
+static const char *ram_used(void);
+static const char *ram_total(void);
+static const char *run_command(const char *cmd);
+static const char *swap_free(void);
+static const char *swap_perc(void);
+static const char *swap_used(void);
+static const char *swap_total(void);
+static const char *temp(const char *file);
+static const char *uid(void);
+static const char *uptime(void);
+static const char *username(void);
+static const char *vol_perc(const char *card);
+static const char *wifi_perc(const char *iface);
+static const char *wifi_essid(const char *iface);
 static void sighandler(const int signo);
 static void usage(const int eval);
 
@@ -78,30 +78,25 @@ static Display *dpy;
 
 #include "config.h"
 
-static char *
-smprintf(const char *fmt, ...)
+static char buf[MAXLEN];
+
+static const char *
+bprintf(const char *fmt, ...)
 {
 	va_list ap;
-	char *ret;
-	int len;
+	size_t len;
 
 	va_start(ap, fmt);
-	len = vsnprintf(NULL, 0, fmt, ap);
+	len = vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 	va_end(ap);
 
-	ret = malloc(++len);
-	if (ret == NULL) {
-		err(1, "malloc");
-	}
+	if (len >= sizeof(buf))
+		buf[sizeof(buf)-1] = '\0';
 
-	va_start(ap, fmt);
-	vsnprintf(ret, len, fmt, ap);
-	va_end(ap);
-
-	return ret;
+	return buf;
 }
 
-static char *
+static const char *
 battery_perc(const char *bat)
 {
 	int perc;
@@ -112,15 +107,15 @@ battery_perc(const char *bat)
 	fp = fopen(path, "r");
 	if (fp == NULL) {
 		warn("Failed to open file %s", path);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "%i", &perc);
 	fclose(fp);
 
-	return smprintf("%d", perc);
+	return bprintf("%d", perc);
 }
 
-static char *
+static const char *
 battery_power(const char *bat)
 {
 	char path[PATH_MAX];
@@ -131,15 +126,15 @@ battery_power(const char *bat)
 	fp = fopen(path, "r");
 	if (fp == NULL) {
 		warn("Failed to open file %s", path);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "%i", &watts);
 	fclose(fp);
 
-	return smprintf("%d", (watts + 500000) / 1000000);
+	return bprintf("%d", (watts + 500000) / 1000000);
 }
 
-static char *
+static const char *
 battery_state(const char *bat)
 {
 	char path[PATH_MAX];
@@ -150,25 +145,25 @@ battery_state(const char *bat)
 	fp = fopen(path, "r");
 	if (fp == NULL) {
 		warn("Failed to open file %s", path);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "%12s", state);
 	fclose(fp);
 
 	if (strcmp(state, "Charging") == 0) {
-		return smprintf("+");
+		return "+";
 	} else if (strcmp(state, "Discharging") == 0) {
-		return smprintf("-");
+		return "-";
 	} else if (strcmp(state, "Full") == 0) {
-		return smprintf("=");
+		return "=";
 	} else if (strcmp(state, "Unknown") == 0) {
-		return smprintf("/");
+		return "/";
 	} else {
-		return smprintf("?");
+		return "?";
 	}
 }
 
-static char *
+static const char *
 cpu_freq(void)
 {
 	int freq;
@@ -177,15 +172,15 @@ cpu_freq(void)
 	fp = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "%i", &freq);
 	fclose(fp);
 
-	return smprintf("%d", (freq + 500) / 1000);
+	return bprintf("%d", (freq + 500) / 1000);
 }
 
-static char *
+static const char *
 cpu_perc(void)
 {
 	int perc;
@@ -195,7 +190,7 @@ cpu_perc(void)
 	fp = fopen("/proc/stat", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/stat");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2], &a[3]);
 	fclose(fp);
@@ -206,43 +201,41 @@ cpu_perc(void)
 	fp = fopen("/proc/stat", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/stat");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2], &b[3]);
 	fclose(fp);
 
 	perc = 100 * ((b[0]+b[1]+b[2]) - (a[0]+a[1]+a[2])) / ((b[0]+b[1]+b[2]+b[3]) - (a[0]+a[1]+a[2]+a[3]));
-	return smprintf("%d", perc);
+	return bprintf("%d", perc);
 }
 
-static char *
+static const char *
 datetime(const char *fmt)
 {
 	time_t t;
-	char str[80];
 
 	t = time(NULL);
-	if (strftime(str, sizeof(str), fmt, localtime(&t)) == 0) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if (strftime(buf, sizeof(buf), fmt, localtime(&t)) == 0)
+		return UNKNOWN_STR;
 
-	return smprintf("%s", str);
+	return buf;
 }
 
-static char *
+static const char *
 disk_free(const char *mnt)
 {
 	struct statvfs fs;
 
 	if (statvfs(mnt, &fs) < 0) {
 		warn("Failed to get filesystem info");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
-	return smprintf("%f", (float)fs.f_bsize * (float)fs.f_bfree / 1024 / 1024 / 1024);
+	return bprintf("%f", (float)fs.f_bsize * (float)fs.f_bfree / 1024 / 1024 / 1024);
 }
 
-static char *
+static const char *
 disk_perc(const char *mnt)
 {
 	int perc;
@@ -250,41 +243,41 @@ disk_perc(const char *mnt)
 
 	if (statvfs(mnt, &fs) < 0) {
 		warn("Failed to get filesystem info");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
 	perc = 100 * (1.0f - ((float)fs.f_bfree / (float)fs.f_blocks));
 
-	return smprintf("%d", perc);
+	return bprintf("%d", perc);
 }
 
-static char *
+static const char *
 disk_total(const char *mnt)
 {
 	struct statvfs fs;
 
 	if (statvfs(mnt, &fs) < 0) {
 		warn("Failed to get filesystem info");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
-	return smprintf("%f", (float)fs.f_bsize * (float)fs.f_blocks / 1024 / 1024 / 1024);
+	return bprintf("%f", (float)fs.f_bsize * (float)fs.f_blocks / 1024 / 1024 / 1024);
 }
 
-static char *
+static const char *
 disk_used(const char *mnt)
 {
 	struct statvfs fs;
 
 	if (statvfs(mnt, &fs) < 0) {
 		warn("Failed to get filesystem info");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
-	return smprintf("%f", (float)fs.f_bsize * ((float)fs.f_blocks - (float)fs.f_bfree) / 1024 / 1024 / 1024);
+	return bprintf("%f", (float)fs.f_bsize * ((float)fs.f_blocks - (float)fs.f_bfree) / 1024 / 1024 / 1024);
 }
 
-static char *
+static const char *
 entropy(void)
 {
 	int num;
@@ -293,34 +286,32 @@ entropy(void)
 	fp= fopen("/proc/sys/kernel/random/entropy_avail", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/sys/kernel/random/entropy_avail");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "%d", &num);
 	fclose(fp);
 
-	return smprintf("%d", num);
+	return bprintf("%d", num);
 }
 
-static char *
+static const char *
 gid(void)
 {
-	return smprintf("%d", getgid());
+	return bprintf("%d", getgid());
 }
 
-static char *
+static const char *
 hostname(void)
 {
-	char buf[HOST_NAME_MAX];
-
 	if (gethostname(buf, sizeof(buf)) == -1) {
 		warn("hostname");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
-	return smprintf("%s", buf);
+	return buf;
 }
 
-static char *
+static const char *
 ip(const char *iface)
 {
 	struct ifaddrs *ifaddr, *ifa;
@@ -329,7 +320,7 @@ ip(const char *iface)
 
 	if (getifaddrs(&ifaddr) == -1) {
 		warn("Failed to get IP address for interface %s", iface);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
 	for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
@@ -340,30 +331,30 @@ ip(const char *iface)
 		if ((strcmp(ifa->ifa_name, iface) == 0) && (ifa->ifa_addr->sa_family == AF_INET)) {
 			if (s != 0) {
 				warnx("Failed to get IP address for interface %s", iface);
-				return smprintf("%s", UNKNOWN_STR);
+				return UNKNOWN_STR;
 			}
-			return smprintf("%s", host);
+			return bprintf("%s", host);
 		}
 	}
 
 	freeifaddrs(ifaddr);
 
-	return smprintf("%s", UNKNOWN_STR);
+	return UNKNOWN_STR;
 }
 
-static char *
+static const char *
 kernel_release(void)
 {
 	struct utsname udata;
 
 	if (uname(&udata) < 0) {
-		return smprintf(UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
-	return smprintf("%s", udata.release);
+	return bprintf("%s", udata.release);
 }
 
-static char *
+static const char *
 keyboard_indicators(void)
 {
 	Display *dpy = XOpenDisplay(NULL);
@@ -373,33 +364,30 @@ keyboard_indicators(void)
 
 	switch (state.led_mask) {
 		case 1:
-			return smprintf("c");
-			break;
+			return "c";
 		case 2:
-			return smprintf("n");
-			break;
+			return "n";
 		case 3:
-			return smprintf("cn");
-			break;
+			return "cn";
 		default:
-			return smprintf("");
+			return "";
 	}
 }
 
-static char *
+static const char *
 load_avg(void)
 {
 	double avgs[3];
 
 	if (getloadavg(avgs, 3) < 0) {
 		warnx("Failed to get the load avg");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
-	return smprintf("%.2f %.2f %.2f", avgs[0], avgs[1], avgs[2]);
+	return bprintf("%.2f %.2f %.2f", avgs[0], avgs[1], avgs[2]);
 }
 
-static char *
+static const char *
 ram_free(void)
 {
 	long free;
@@ -408,15 +396,15 @@ ram_free(void)
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/meminfo");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "MemFree: %ld kB\n", &free);
 	fclose(fp);
 
-	return smprintf("%f", (float)free / 1024 / 1024);
+	return bprintf("%f", (float)free / 1024 / 1024);
 }
 
-static char *
+static const char *
 ram_perc(void)
 {
 	long total, free, buffers, cached;
@@ -425,7 +413,7 @@ ram_perc(void)
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/meminfo");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "MemTotal: %ld kB\n", &total);
 	fscanf(fp, "MemFree: %ld kB\n", &free);
@@ -433,10 +421,10 @@ ram_perc(void)
 	fscanf(fp, "Cached: %ld kB\n", &cached);
 	fclose(fp);
 
-	return smprintf("%d", 100 * ((total - free) - (buffers + cached)) / total);
+	return bprintf("%d", 100 * ((total - free) - (buffers + cached)) / total);
 }
 
-static char *
+static const char *
 ram_total(void)
 {
 	long total;
@@ -445,15 +433,15 @@ ram_total(void)
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/meminfo");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "MemTotal: %ld kB\n", &total);
 	fclose(fp);
 
-	return smprintf("%f", (float)total / 1024 / 1024);
+	return bprintf("%f", (float)total / 1024 / 1024);
 }
 
-static char *
+static const char *
 ram_used(void)
 {
 	long free, total, buffers, cached;
@@ -462,7 +450,7 @@ ram_used(void)
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/meminfo");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "MemTotal: %ld kB\n", &total);
 	fscanf(fp, "MemFree: %ld kB\n", &free);
@@ -470,184 +458,159 @@ ram_used(void)
 	fscanf(fp, "Cached: %ld kB\n", &cached);
 	fclose(fp);
 
-	return smprintf("%f", (float)(total - free - buffers - cached) / 1024 / 1024);
+	return bprintf("%f", (float)(total - free - buffers - cached) / 1024 / 1024);
 }
 
-static char *
+static const char *
 run_command(const char *cmd)
 {
 	char *nlptr;
 	FILE *fp;
-	char buf[1024] = UNKNOWN_STR;
 
 	fp = popen(cmd, "r");
 	if (fp == NULL) {
 		warn("Failed to get command output for %s", cmd);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
-	fgets(buf, sizeof(buf), fp);
+	fgets(buf, sizeof(buf) - 1, fp);
 	pclose(fp);
-	buf[sizeof(buf) - 1] = '\0';
-
-	if ((nlptr = strrchr(buf, '\n')) != NULL) {
+	if ((nlptr = strrchr(buf, '\n')) != NULL)
 		nlptr[0] = '\0';
-	}
 
-	return smprintf("%s", buf);
+	return buf[0] ? buf : UNKNOWN_STR;
 }
 
-static char *
+static const char *
 swap_free(void)
 {
 	long total, free;
 	FILE *fp;
-	char buf[2048];
 	size_t bytes_read;
 	char *match;
 
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/meminfo");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
 	if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1, fp)) == 0) {
 		warn("swap_free: read error");
 		fclose(fp);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
-
-	buf[bytes_read] = '\0';
 	fclose(fp);
 
-	if ((match = strstr(buf, "SwapTotal")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapTotal")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-	if ((match = strstr(buf, "SwapFree")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapFree")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapFree: %ld kB\n", &free);
 
-	return smprintf("%f", (float)free / 1024 / 1024);
+	return bprintf("%f", (float)free / 1024 / 1024);
 }
 
-static char *
+static const char *
 swap_perc(void)
 {
 	long total, free, cached;
 	FILE *fp;
-	char buf[2048];
 	size_t bytes_read;
 	char *match;
 
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/meminfo");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
 	if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1, fp)) == 0) {
 		warn("swap_perc: read error");
 		fclose(fp);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
-
-	buf[bytes_read] = '\0';
 	fclose(fp);
 
-	if ((match = strstr(buf, "SwapTotal")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapTotal")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-	if ((match = strstr(buf, "SwapCached")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapCached")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapCached: %ld kB\n", &cached);
 
-	if ((match = strstr(buf, "SwapFree")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapFree")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapFree: %ld kB\n", &free);
 
-	return smprintf("%d", 100 * (total - free - cached) / total);
+	return bprintf("%d", 100 * (total - free - cached) / total);
 }
 
-static char *
+static const char *
 swap_total(void)
 {
 	long total;
 	FILE *fp;
-	char buf[2048];
 	size_t bytes_read;
 	char *match;
 
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/meminfo");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1, fp)) == 0) {
 		warn("swap_total: read error");
 		fclose(fp);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
-
-	buf[bytes_read] = '\0';
 	fclose(fp);
 
-	if ((match = strstr(buf, "SwapTotal")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapTotal")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-	return smprintf("%f", (float)total / 1024 / 1024);
+	return bprintf("%f", (float)total / 1024 / 1024);
 }
 
-static char *
+static const char *
 swap_used(void)
 {
 	long total, free, cached;
 	FILE *fp;
-	char buf[2048];
 	size_t bytes_read;
 	char *match;
 
 	fp = fopen("/proc/meminfo", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/meminfo");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	if ((bytes_read = fread(buf, sizeof(char), sizeof(buf) - 1, fp)) == 0) {
 		warn("swap_used: read error");
 		fclose(fp);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
-
-	buf[bytes_read] = '\0';
 	fclose(fp);
 
-	if ((match = strstr(buf, "SwapTotal")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapTotal")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapTotal: %ld kB\n", &total);
 
-	if ((match = strstr(buf, "SwapCached")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapCached")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapCached: %ld kB\n", &cached);
 
-	if ((match = strstr(buf, "SwapFree")) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((match = strstr(buf, "SwapFree")) == NULL)
+		return UNKNOWN_STR;
 	sscanf(match, "SwapFree: %ld kB\n", &free);
 
-	return smprintf("%f", (float)(total - free - cached) / 1024 / 1024);
+	return bprintf("%f", (float)(total - free - cached) / 1024 / 1024);
 }
 
-static char *
+static const char *
 temp(const char *file)
 {
 	int temp;
@@ -656,15 +619,15 @@ temp(const char *file)
 	fp = fopen(file, "r");
 	if (fp == NULL) {
 		warn("Failed to open file %s", file);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fscanf(fp, "%d", &temp);
 	fclose(fp);
 
-	return smprintf("%d", temp / 1000);
+	return bprintf("%d", temp / 1000);
 }
 
-static char *
+static const char *
 uptime(void)
 {
 	struct sysinfo info;
@@ -675,30 +638,30 @@ uptime(void)
 	h = info.uptime / 3600;
 	m = (info.uptime - h * 3600 ) / 60;
 
-	return smprintf("%dh %dm", h, m);
+	return bprintf("%dh %dm", h, m);
 }
 
-static char *
+static const char *
 username(void)
 {
 	struct passwd *pw = getpwuid(geteuid());
 
 	if (pw == NULL) {
 		warn("Failed to get username");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
-	return smprintf("%s", pw->pw_name);
+	return bprintf("%s", pw->pw_name);
 }
 
-static char *
+static const char *
 uid(void)
 {
-	return smprintf("%d", geteuid());
+	return bprintf("%d", geteuid());
 }
 
 
-static char *
+static const char *
 vol_perc(const char *card)
 {
 	unsigned int i;
@@ -708,34 +671,33 @@ vol_perc(const char *card)
 	afd = open(card, O_RDONLY | O_NONBLOCK);
 	if (afd == -1) {
 		warn("Cannot open %s", card);
-		return smprintf(UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
 	if (ioctl(afd, SOUND_MIXER_READ_DEVMASK, &devmask) == -1) {
 		warn("Cannot get volume for %s", card);
 		close(afd);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	for (i = 0; i < (sizeof(vnames) / sizeof((vnames[0]))); i++) {
 		if (devmask & (1 << i) && !strcmp("vol", vnames[i])) {
 			if (ioctl(afd, MIXER_READ(i), &v) == -1) {
 				warn("vol_perc: ioctl");
 				close(afd);
-				return smprintf("%s", UNKNOWN_STR);
+				return UNKNOWN_STR;
 			}
 		}
 	}
 
 	close(afd);
 
-	return smprintf("%d", v & 0xff);
+	return bprintf("%d", v & 0xff);
 }
 
-static char *
+static const char *
 wifi_perc(const char *iface)
 {
 	int perc;
-	char buf[255];
 	char *datastart;
 	char path[PATH_MAX];
 	char status[5];
@@ -745,38 +707,38 @@ wifi_perc(const char *iface)
 	fp = fopen(path, "r");
 	if (fp == NULL) {
 		warn("Failed to open file %s", path);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	fgets(status, 5, fp);
 	fclose(fp);
 	if(strcmp(status, "up\n") != 0) {
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
 	fp = fopen("/proc/net/wireless", "r");
 	if (fp == NULL) {
 		warn("Failed to open file /proc/net/wireless");
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
-	fgets(buf, sizeof(buf), fp);
-	fgets(buf, sizeof(buf), fp);
-	fgets(buf, sizeof(buf), fp);
+	fgets(buf, sizeof(buf) - 1, fp);
+	fgets(buf, sizeof(buf) - 1, fp);
+	fgets(buf, sizeof(buf) - 1, fp);
 	fclose(fp);
 
-	if ((datastart = strstr(buf, iface)) == NULL) {
-		return smprintf("%s", UNKNOWN_STR);
-	}
+	if ((datastart = strstr(buf, iface)) == NULL)
+		return UNKNOWN_STR;
+
 	datastart = (datastart+(strlen(iface)+1));
 	sscanf(datastart + 1, " %*d   %d  %*d  %*d		  %*d	   %*d		%*d		 %*d	  %*d		 %*d", &perc);
 
-	return smprintf("%d", perc);
+	return bprintf("%d", perc);
 }
 
-static char *
+static const char *
 wifi_essid(const char *iface)
 {
-	char id[IW_ESSID_MAX_SIZE+1];
+	static char id[IW_ESSID_MAX_SIZE+1];
 	int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
 	struct iwreq wreq;
 
@@ -786,20 +748,20 @@ wifi_essid(const char *iface)
 
 	if (sockfd == -1) {
 		warn("Failed to get ESSID for interface %s", iface);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 	wreq.u.essid.pointer = id;
 	if (ioctl(sockfd,SIOCGIWESSID, &wreq) == -1) {
 		warn("Failed to get ESSID for interface %s", iface);
-		return smprintf("%s", UNKNOWN_STR);
+		return UNKNOWN_STR;
 	}
 
 	close(sockfd);
 
-	if (strcmp((char *)wreq.u.essid.pointer, "") == 0)
-		return smprintf("%s", UNKNOWN_STR);
+	if (strcmp(id, "") == 0)
+		return UNKNOWN_STR;
 	else
-		return smprintf("%s", (char *)wreq.u.essid.pointer);
+		return id;
 }
 
 static void
@@ -821,10 +783,11 @@ int
 main(int argc, char *argv[])
 {
 	unsigned short int i;
-	char status_string[2048];
-	char *res, *element;
+	char status_string[MAXLEN];
+	char *element;
 	struct arg argument;
 	struct sigaction act;
+	size_t len;
 
 	ARGBEGIN {
 		case 'd':
@@ -866,21 +829,17 @@ main(int argc, char *argv[])
 	while (!done) {
 		status_string[0] = '\0';
 
-		for (i = 0; i < sizeof(args) / sizeof(args[0]); ++i) {
+		for (element = status_string, i = len = 0;
+		     i < sizeof(args) / sizeof(args[0]);
+		     ++i, element += len) {
 			argument = args[i];
-			if (argument.args == NULL) {
-				res = argument.func();
-			} else {
-				res = argument.func(argument.args);
-			}
-			element = smprintf(argument.fmt, res);
-			if (element == NULL) {
-				element = smprintf("%s", UNKNOWN_STR);
-				warnx("Failed to format output");
+			len = snprintf(element, sizeof(status_string)-1 - len,
+			               argument.fmt,
+			               argument.func(argument.args));
+			if (len >= sizeof(status_string)) {
+				status_string[sizeof(status_string)-1] = '\0';
+				break;
 			}
-			strncat(status_string, element, sizeof(status_string) - strlen(status_string) - 1);
-			free(res);
-			free(element);
 		}
 
 		if (oflag) {