use a static buffer instead of dynamic memory

diff --git a/config.def.h b/config.def.h
index be60df8702c51fe2ebd721048c4b68082d273b56..a961dbc39ab61ce5734edf19084bf876bc14690e 100644 (file)
--- a/config.def.h
+++ b/config.def.h
@@ -4,7 +4,10 @@
 #define UPDATE_INTERVAL 1
 
 /* text to show if no value can be retrieved */
-#define UNKNOWN_STR     "n/a"
+#define UNKNOWN_STR "n/a"
+
+/* maximum output string length */
+#define MAXLEN 2048
 
 /* statusbar
 - battery_perc (battery percentage) [argument: battery name]

diff --git a/slstatus.c b/slstatus.c
index cb4798b070e3a1b21c39d59bbaf45d5b8d80217f..b5924469933bed5352a17ee646d327de98a5d84f 100644 (file)
--- 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) {