X-Git-Url: https://git.xinqibao.xyz/slstatus.git/blobdiff_plain/6b2b839cfda8ebf34bbf9d820718f60154b42871..9078fb351dc3d1e2eac261ec185acef1f66180bc:/slstatus.c

diff --git a/slstatus.c b/slstatus.c
index 7af2f04..4b69cc6 100644
--- a/slstatus.c
+++ b/slstatus.c
@@ -1,334 +1,699 @@
 /* See LICENSE file for copyright and license details. */
 
+/* global libraries */
 #include <alsa/asoundlib.h>
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <ifaddrs.h>
+#include <limits.h>
+#include <locale.h>
+#include <netdb.h>
+#include <pwd.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include <sys/socket.h>
 #include <time.h>
 #include <unistd.h>
 #include <X11/Xlib.h>
 
+/* local headers */
+#include "slstatus.h"
 #include "config.h"
 
-char *smprintf(char *fmt, ...);
+/* set statusbar */
+void
+setstatus(const char *str)
+{
+    /* set WM_NAME via X11 */
+    XStoreName(dpy, DefaultRootWindow(dpy), str);
+    XSync(dpy, False);
+}
 
-void setstatus(char *str);
+/* smprintf function */
+char *
+smprintf(const char *fmt, ...)
+{
+    va_list fmtargs;
+    char *ret = NULL;
 
-char *wifi_signal();
-char *battery();
-char *cpu_usage();
-char *cpu_temperature();
-char *ram_usage();
-char *volume();
-char *datetime();
+    va_start(fmtargs, fmt);
+    if (vasprintf(&ret, fmt, fmtargs) < 0)
+        return NULL;
+    va_end(fmtargs);
 
-static Display *dpy;
+    return ret;
+}
 
-/* smprintf function */
+/* battery percentage */
 char *
-smprintf(char *fmt, ...)
+battery_perc(const char *battery)
 {
-	va_list fmtargs;
-	char *ret;
-	int len;
+    int now, full, perc;
+    char batterynowfile[64] = "";
+    char batteryfullfile[64] = "";
+    FILE *fp;
+
+    /* generate battery nowfile path */
+    strcat(batterynowfile, batterypath);
+    strcat(batterynowfile, battery);
+    strcat(batterynowfile, "/");
+    strcat(batterynowfile, batterynow);
+
+    /* generate battery fullfile path */
+    strcat(batteryfullfile, batterypath);
+    strcat(batteryfullfile, battery);
+    strcat(batteryfullfile, "/");
+    strcat(batteryfullfile, batteryfull);
+
+    /* open battery now file */
+    if (!(fp = fopen(batterynowfile, "r"))) {
+        fprintf(stderr, "Error opening battery file.%s",batterynowfile);
+        return smprintf("n/a");
+    }
+
+    /* read value */
+    fscanf(fp, "%i", &now);
+
+    /* close battery now file */
+    fclose(fp);
+
+    /* open battery full file */
+    if (!(fp = fopen(batteryfullfile, "r"))) {
+        fprintf(stderr, "Error opening battery file.");
+        return smprintf("n/a");
+    }
 
-	va_start(fmtargs, fmt);
-	len = vsnprintf(NULL, 0, fmt, fmtargs);
-	va_end(fmtargs);
+    /* read value */
+    fscanf(fp, "%i", &full);
 
-	ret = malloc(++len);
-	if (ret == NULL) {
-		fprintf(stderr, "Malloc error.");
-		exit(1);
-	}
+    /* close battery full file */
+    fclose(fp);
 
-	va_start(fmtargs, fmt);
-	vsnprintf(ret, len, fmt, fmtargs);
-	va_end(fmtargs);
+    /* calculate percent */
+    perc = now / (full / 100);
 
-	return ret;
+    /* return perc as string */
+    return smprintf("%d%%", perc);
 }
 
-/* set statusbar (WM_NAME) */
-void
-setstatus(char *str)
+/* cpu percentage */
+char *
+cpu_perc(const char *null)
 {
-	XStoreName(dpy, DefaultRootWindow(dpy), str);
-	XSync(dpy, False);
+    int perc;
+    long double a[4], b[4];
+    FILE *fp;
+
+    /* open stat file */
+    if (!(fp = fopen("/proc/stat","r"))) {
+        fprintf(stderr, "Error opening stat file.");
+        return smprintf("n/a");
+    }
+
+    /* read values */
+    fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2], &a[3]);
+
+    /* close stat file */
+    fclose(fp);
+
+    /* wait a second (for avg values) */
+    sleep(1);
+
+    /* open stat file */
+    if (!(fp = fopen("/proc/stat","r"))) {
+        fprintf(stderr, "Error opening stat file.");
+        return smprintf("n/a");
+    }
+
+    /* read values */
+    fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2], &b[3]);
+
+    /* close stat file */
+    fclose(fp);
+
+    /* calculate avg in this second */
+    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 perc as string */
+    return smprintf("%d%%", perc);
 }
 
-/* alsa volume percentage */
+/* date and time */
 char *
-volume()
+datetime(const char *timeformat)
 {
-        int mute = 0;
-        long vol = 0, max = 0, min = 0;
-        
-        /* get volume from alsa */
-        snd_mixer_t *handle;
-        snd_mixer_elem_t *pcm_mixer, *mas_mixer;
-        snd_mixer_selem_id_t *vol_info, *mute_info;
-        snd_mixer_open(&handle, 0);
-        snd_mixer_attach(handle, soundcard);
-        snd_mixer_selem_register(handle, NULL, NULL);
-        snd_mixer_load(handle);
-        snd_mixer_selem_id_malloc(&vol_info);
-        snd_mixer_selem_id_malloc(&mute_info);
-        snd_mixer_selem_id_set_name(vol_info, channel);
-        snd_mixer_selem_id_set_name(mute_info, channel);
-        pcm_mixer = snd_mixer_find_selem(handle, vol_info);
-        mas_mixer = snd_mixer_find_selem(handle, mute_info);
-        snd_mixer_selem_get_playback_volume_range((snd_mixer_elem_t *)pcm_mixer,
-                        &min, &max);
-        snd_mixer_selem_get_playback_volume((snd_mixer_elem_t *)pcm_mixer,
-                        SND_MIXER_SCHN_MONO, &vol);
-        snd_mixer_selem_get_playback_switch(mas_mixer, SND_MIXER_SCHN_MONO,
-                        &mute);
-        if (vol_info)
-                snd_mixer_selem_id_free(vol_info);
-        if (mute_info)
-                snd_mixer_selem_id_free(mute_info);
-        if (handle)
-                snd_mixer_close(handle);
-        
-        /* return the string (mute) */
-        if (!mute)
-            return "mute";
-        else
-            return smprintf("%d%%", (vol * 100) / max);
+    time_t tm;
+    size_t bufsize = 64;
+    char *buf = malloc(bufsize);
+    if (buf == NULL) {
+        fprintf(stderr, "Failed to get date/time");
+        return smprintf("n/a");
+    }
+
+    /* get time in format */
+    time(&tm);
+    setlocale(LC_TIME, "");
+    if(!strftime(buf, bufsize, timeformat, localtime(&tm))) {
+        setlocale(LC_TIME, "C");
+        fprintf(stderr, "Strftime failed.\n");
+        return smprintf("n/a");
+    }
+
+    setlocale(LC_TIME, "C");
+    /* return time */
+    char *ret = smprintf("%s", buf);
+    free(buf);
+    return ret;
 }
 
-/* cpu temperature */
+/* disk free */
 char *
-cpu_temperature()
+disk_free(const char *mountpoint)
 {
-    int temperature;
-    FILE *fp;
+    struct statvfs fs;
 
-    /* open temperature file */
-    if (!(fp = fopen(tempfile, "r"))) {
-        fprintf(stderr, "Could not open temperature file.\n");
-        exit(1);
+    /* try to open mountpoint */
+    if (statvfs(mountpoint, &fs) < 0) {
+        fprintf(stderr, "Could not get filesystem info.\n");
+        return smprintf("n/a");
     }
 
-    /* extract temperature */
-    fscanf(fp, "%d", &temperature);
+    /* return free */
+    return smprintf("%f", (float)fs.f_bsize * (float)fs.f_bfree / 1024 / 1024 / 1024);
+}
 
-    /* close temperature file */
-    fclose(fp);
+/* disk usage percentage */
+char *
+disk_perc(const char *mountpoint)
+{
+    int perc = 0;
+    struct statvfs fs;
 
-    /* return temperature in degrees */
-    return smprintf("%d°C", temperature / 1000);
+    /* try to open mountpoint */
+    if (statvfs(mountpoint, &fs) < 0) {
+        fprintf(stderr, "Could not get filesystem info.\n");
+        return smprintf("n/a");
+    }
+
+    /* calculate percent */
+    perc = 100 * (1.0f - ((float)fs.f_bfree / (float)fs.f_blocks));
+
+    /* return perc */
+    return smprintf("%d%%", perc);
 }
 
-/* wifi percentage */
+/* disk total */
 char *
-wifi_signal()
+disk_total(const char *mountpoint)
 {
-    int bufsize = 255;
-	int strength;
-	char buf[bufsize];
-	char *datastart;
-    char path_start[16] = "/sys/class/net/";
-    char path_end[11] = "/operstate";
-    char path[32];
-    char status[5];
-	FILE *fp;
+    struct statvfs fs;
 
-    /* generate the path name */
-    strcat(path, path_start);
-    strcat(path, wificard);
-    strcat(path, path_end);
-
-    /* open wifi file */
-    if(!(fp = fopen(path, "r"))) {
-        fprintf(stderr, "Error opening wifi operstate file.");
-        exit(1);
+    /* try to open mountpoint */
+    if (statvfs(mountpoint, &fs) < 0) {
+        fprintf(stderr, "Could not get filesystem info.\n");
+        return smprintf("n/a");
     }
 
-    /* read the status */
-    fgets(status, 5, fp);
+    /* return total */
+    return smprintf("%f", (float)fs.f_bsize * (float)fs.f_blocks / 1024 / 1024 / 1024);
+}
 
-    /* close wifi file */
-    fclose(fp);
+/* disk used */
+char *
+disk_used(const char *mountpoint)
+{
+    struct statvfs fs;
 
-    /* check if interface down */
-    if(strcmp(status, "up\n") != 0){
-        return "n/a";
+    /* try to open mountpoint */
+    if (statvfs(mountpoint, &fs) < 0) {
+        fprintf(stderr, "Could not get filesystem info.\n");
+        return smprintf("n/a");
     }
 
-    /* open wifi file */
-    if (!(fp = fopen("/proc/net/wireless", "r"))) {
-        fprintf(stderr, "Error opening wireless file.");
-        exit(1);
+    /* return used */
+    return smprintf("%f", (float)fs.f_bsize * ((float)fs.f_blocks - (float)fs.f_bfree) / 1024 / 1024 / 1024);
+}
+
+/* entropy available */
+char *
+entropy(const char *null)
+{
+    int entropy = 0;
+    FILE *fp;
+
+    /* open entropy file */
+    if (!(fp = fopen("/proc/sys/kernel/random/entropy_avail", "r"))) {
+        fprintf(stderr, "Could not open entropy file.\n");
+        return smprintf("n/a");
     }
 
-    /* extract the signal strength */
-	fgets(buf, bufsize, fp);
-	fgets(buf, bufsize, fp);
-	fgets(buf, bufsize, fp);
-	if ((datastart = strstr(buf, "wlp3s0:")) != NULL) {
-		datastart = strstr(buf, ":");
-		sscanf(datastart + 1, " %*d   %d  %*d  %*d        %*d      %*d      %*d      %*d      %*d        %*d",
-	           &strength);
-	}
+    /* extract entropy */
+    fscanf(fp, "%d", &entropy);
 
-    /* close wifi file */
-	fclose(fp);
+    /* close entropy file */
+    fclose(fp);
 
-    /* return strength in percent */
-    return smprintf("%d%%", strength);
+    /* return entropy */
+    return smprintf("%d", entropy);
 }
 
-/* battery percentage */
+/* gid */
 char *
-battery()
+gid(const char *null)
 {
-	int batt_now, batt_full, batt_perc;
-	FILE *fp;
+    gid_t gid;
 
-    /* open battery now file */
-	if (!(fp = fopen(batterynowfile, "r"))) {
-        fprintf(stderr, "Error opening battery file.");
-        exit(1);
+    if ((gid = getgid()) < 0) {
+        fprintf(stderr, "Could no get gid.");
+        return smprintf("n/a");
+    } else {
+        return smprintf("%d", gid);
     }
 
-    /* read value */
-	fscanf(fp, "%i", &batt_now);
+    return smprintf("n/a");
+}
 
-    /* close battery now file */
-	fclose(fp);
-	
-    /* open battery full file */
-	if (!(fp = fopen(batteryfullfile, "r"))) {
-        fprintf(stderr, "Error opening battery file.");
-        exit(1);
-    }
+/* hostname */
+char *
+hostname(const char *null)
+{
+    char hostname[HOST_NAME_MAX];
+    FILE *fp;
 
-    /* read value */
-	fscanf(fp, "%i", &batt_full);
+    /* open hostname file */
+    if (!(fp = fopen("/proc/sys/kernel/hostname", "r"))) {
+        fprintf(stderr, "Could not open hostname file.\n");
+        return smprintf("n/a");
+    }
 
-    /* close battery full file */
-	fclose(fp);
+    /* extract hostname */
+    fscanf(fp, "%s\n", hostname);
 
-    /* calculate percent */
-	batt_perc = batt_now / (batt_full / 100);
+    /* close hostname file */
+    fclose(fp);
 
-    /* return batt_perc as string */
-	return smprintf("%d%%", batt_perc);
+    /* return entropy */
+    return smprintf("%s", hostname);
 }
 
-/* date and time */
+/* ip address */
 char *
-datetime()
+ip(const char *interface)
 {
-	time_t tm;
-	size_t bufsize = 19;
-	char *buf = malloc(bufsize);
+    struct ifaddrs *ifaddr, *ifa;
+    int s;
+    char host[NI_MAXHOST];
+
+    /* check if getting ip address works */
+    if (getifaddrs(&ifaddr) == -1)
+    {
+        fprintf(stderr, "Error getting IP address.");
+        return smprintf("n/a");
+    }
 
-    /* get time in format */
-	time(&tm);
-	if(!strftime(buf, bufsize, timeformat, localtime(&tm))) {
-		fprintf(stderr, "Strftime failed.\n");
-		exit(1);
-	}
+    /* get the ip address */
+    for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next)
+    {
+        if (ifa->ifa_addr == NULL)
+            continue;
+
+        s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
+
+        if ((strcmp(ifa->ifa_name, interface) == 0) && (ifa->ifa_addr->sa_family == AF_INET))
+        {
+            if (s != 0)
+            {
+                fprintf(stderr, "Error getting IP address.");
+                return smprintf("n/a");
+            }
+            return smprintf("%s", host);
+        }
+    }
 
-    /* return time */
-	return buf;
+    /* free the address */
+    freeifaddrs(ifaddr);
+
+    /* return n/a if nothing works */
+    return smprintf("n/a");
 }
 
-/* cpu percentage */
+/* ram free */
 char *
-cpu_usage()
+ram_free(const char *null)
 {
-    int cpu_perc;
-    long double a[4], b[4];
+    long free;
     FILE *fp;
 
-    /* open stat file */
-	if (!(fp = fopen("/proc/stat","r"))) {
-        fprintf(stderr, "Error opening stat file.");
-        exit(1);
+    /* open meminfo file */
+    if (!(fp = fopen("/proc/meminfo", "r"))) {
+        fprintf(stderr, "Error opening meminfo file.");
+        return smprintf("n/a");
     }
 
-    /* read values */
-    fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2], &a[3]);
+    /* read the values */
+    fscanf(fp, "MemTotal: %*d kB\n");
+    fscanf(fp, "MemFree: %ld kB\n", &free);
 
-    /* close stat file */
+    /* close meminfo file */
     fclose(fp);
 
-    /* wait a second (for avg values) */
-    sleep(1);
+    /* return free ram as string */
+    return smprintf("%f", (float)free / 1024 / 1024);
+}
 
-    /* open stat file */
-	if (!(fp = fopen("/proc/stat","r"))) {
-        fprintf(stderr, "Error opening stat file.");
-        exit(1);
+/* ram percentage */
+char *
+ram_perc(const char *null)
+{
+    int perc;
+    long total, free, buffers, cached;
+    FILE *fp;
+
+    /* open meminfo file */
+    if (!(fp = fopen("/proc/meminfo", "r"))) {
+        fprintf(stderr, "Error opening meminfo file.");
+        return smprintf("n/a");
     }
 
-    /* read values */
-    fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2], &b[3]);
+    /* read the values */
+    fscanf(fp, "MemTotal: %ld kB\n", &total);
+    fscanf(fp, "MemFree: %ld kB\n", &free);
+    fscanf(fp, "MemAvailable: %ld kB\nBuffers: %ld kB\n", &buffers, &buffers);
+    fscanf(fp, "Cached: %ld kB\n", &cached);
 
-    /* close stat file */
+    /* close meminfo file */
     fclose(fp);
 
-    /* calculate avg in this second */
-    cpu_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]));
+    /* calculate percentage */
+    perc = 100 * ((total - free) - (buffers + cached)) / total;
 
-    /* return cpu_perc as string */
-    return smprintf("%d%%", cpu_perc);
+    /* return perc as string */
+    return smprintf("%d%%", perc);
 }
 
-/* ram percentage */
+/* ram total */
 char *
-ram_usage()
+ram_total(const char *null)
 {
-    int ram_perc;
-    long total, free, available;
+    long total;
     FILE *fp;
 
     /* open meminfo file */
-	if (!(fp = fopen("/proc/meminfo", "r"))) {
+    if (!(fp = fopen("/proc/meminfo", "r"))) {
         fprintf(stderr, "Error opening meminfo file.");
-        exit(1);
+        return smprintf("n/a");
+    }
+
+    /* read the values */
+    fscanf(fp, "MemTotal: %ld kB\n", &total);
+
+    /* close meminfo file */
+    fclose(fp);
+
+    /* return total ram as string */
+    return smprintf("%f", (float)total / 1024 / 1024);
+}
+
+/* ram used */
+char *
+ram_used(const char *null)
+{
+    long free, total, buffers, cached, used;
+    FILE *fp;
+
+    /* open meminfo file */
+    if (!(fp = fopen("/proc/meminfo", "r"))) {
+        fprintf(stderr, "Error opening meminfo file.");
+        return smprintf("n/a");
     }
 
     /* read the values */
     fscanf(fp, "MemTotal: %ld kB\n", &total);
     fscanf(fp, "MemFree: %ld kB\n", &free);
-    fscanf(fp, "MemAvailable: %ld kB\n", &available);
+    fscanf(fp, "MemAvailable: %ld kB\nBuffers: %ld kB\n", &buffers, &buffers);
+    fscanf(fp, "Cached: %ld kB\n", &cached);
 
     /* close meminfo file */
     fclose(fp);
 
-    /* calculate percentage */
-    ram_perc = 100 * (total - available) / total;
+    /* calculate used */
+    used = total - free - buffers - cached;
+
+    /* return used ram as string */
+    return smprintf("%f", (float)used / 1024 / 1024);
+}
+
+/* custom shell command */
+char *
+run_command(const char* command)
+{
+	FILE *fp;
+	char buffer[64];
+
+    /* try to open the command output */
+	if (!(fp = popen(command, "r"))) {
+        fprintf(stderr, "Could not get command output for: %s.\n", command);
+        return smprintf("n/a");
+    }
 
-    /* return ram_perc as string */
-    return smprintf("%d%%",ram_perc);
+    /* get command output text, save it to buffer */
+	fgets(buffer, sizeof(buffer)-1, fp);
+
+    /* close it again */
+	pclose(fp);
+
+    /* add nullchar at the end */
+	buffer[strlen(buffer) - 1] = '\0';
+
+    /* return the output */
+	return smprintf("%s", buffer);
 }
 
+/* temperature */
+char *
+temp(const char *file)
+{
+    int temperature;
+    FILE *fp;
+
+    /* open temperature file */
+    if (!(fp = fopen(file, "r"))) {
+        fprintf(stderr, "Could not open temperature file.\n");
+        return smprintf("n/a");
+    }
+
+    /* extract temperature */
+    fscanf(fp, "%d", &temperature);
+
+    /* close temperature file */
+    fclose(fp);
+
+    /* return temperature in degrees */
+    return smprintf("%d°C", temperature / 1000);
+}
+
+/* username */
+char *
+username(const char *null)
+{
+    register struct passwd *pw;
+    register uid_t uid;
+
+    /* get the values */
+    uid = geteuid ();
+    pw = getpwuid (uid);
+
+    /* if it worked, return */
+    if (pw) {
+        return smprintf("%s", pw->pw_name);
+    }
+    else {
+        fprintf(stderr, "Could not get username.\n");
+        return smprintf("n/a");
+    }
+
+    return smprintf("n/a");
+}
+
+/* uid */
+char *
+uid(const char *null)
+{
+    register uid_t uid;
+
+    /* get the values */
+    uid = geteuid ();
+
+    /* if it worked, return */
+    if (uid) {
+        return smprintf("%d", uid);
+    }
+    else {
+        fprintf(stderr, "Could not get uid.\n");
+        return smprintf("n/a");
+    }
+
+    return smprintf("n/a");
+}
+
+
+/* alsa volume percentage */
+char *
+vol_perc(const char *soundcard)
+{
+    int mute = 0;
+    long vol = 0, max = 0, min = 0;
+    snd_mixer_t *handle;
+    snd_mixer_elem_t *pcm_mixer, *mas_mixer;
+    snd_mixer_selem_id_t *vol_info, *mute_info;
+
+    /* open everything */
+    snd_mixer_open(&handle, 0);
+    snd_mixer_attach(handle, soundcard);
+    snd_mixer_selem_register(handle, NULL, NULL);
+    snd_mixer_load(handle);
+
+    /* prepare everything */
+    snd_mixer_selem_id_malloc(&vol_info);
+    snd_mixer_selem_id_malloc(&mute_info);
+    /* check */
+    if (vol_info == NULL || mute_info == NULL) {
+        fprintf(stderr, "Could not get alsa volume");
+        return smprintf("n/a");
+    }
+    snd_mixer_selem_id_set_name(vol_info, channel);
+    snd_mixer_selem_id_set_name(mute_info, channel);
+    pcm_mixer = snd_mixer_find_selem(handle, vol_info);
+    mas_mixer = snd_mixer_find_selem(handle, mute_info);
+
+    /* get the info */
+    snd_mixer_selem_get_playback_volume_range((snd_mixer_elem_t *)pcm_mixer, &min, &max);
+    snd_mixer_selem_get_playback_volume((snd_mixer_elem_t *)pcm_mixer, SND_MIXER_SCHN_MONO, &vol);
+    snd_mixer_selem_get_playback_switch(mas_mixer, SND_MIXER_SCHN_MONO, &mute);
+
+    /* clean up */
+    if (vol_info) {
+        snd_mixer_selem_id_free(vol_info);
+    }
+    if (mute_info) {
+        snd_mixer_selem_id_free(mute_info);
+    }
+    if (handle) {
+        snd_mixer_close(handle);
+    }
+
+    /* return the string (mute) */
+    if (!mute) {
+        return smprintf("mute");
+    }
+    else {
+        return smprintf("%d%%", (vol * 100) / max);
+    }
+}
+
+/* wifi percentage */
+char *
+wifi_perc(const char *wificard)
+{
+    int bufsize = 255;
+    int strength;
+    char buf[bufsize];
+    char *datastart;
+    char path[64];
+    char status[5];
+    char needle[sizeof wificard + 1];
+    FILE *fp;
+
+    /* generate the path name */
+    memset(path, 0, sizeof path);
+    strcat(path, "/sys/class/net/");
+    strcat(path, wificard);
+    strcat(path, "/operstate");
+
+    /* open wifi file */
+    if(!(fp = fopen(path, "r"))) {
+        fprintf(stderr, "Error opening wifi operstate file.");
+        return smprintf("n/a");
+    }
+
+    /* read the status */
+    fgets(status, 5, fp);
+
+    /* close wifi file */
+    fclose(fp);
+
+    /* check if interface down */
+    if(strcmp(status, "up\n") != 0){
+        return smprintf("n/a");
+    }
+
+    /* open wifi file */
+    if (!(fp = fopen("/proc/net/wireless", "r"))) {
+        fprintf(stderr, "Error opening wireless file.");
+        return smprintf("n/a");
+    }
+
+    /* extract the signal strength */
+    strcpy(needle, wificard);
+    strcat(needle, ":");
+    fgets(buf, bufsize, fp);
+    fgets(buf, bufsize, fp);
+    fgets(buf, bufsize, fp);
+    if ((datastart = strstr(buf, needle)) != NULL) {
+        datastart = strstr(buf, ":");
+        sscanf(datastart + 1, " %*d   %d  %*d  %*d        %*d      %*d      %*d      %*d      %*d        %*d", &strength);
+    }
+
+    /* close wifi file */
+    fclose(fp);
+
+    /* return strength in percent */
+    return smprintf("%d%%", strength);
+}
+
+/* main function */
 int
 main()
 {
-    char status[1024];
+    char status_string[1024];
+    struct arg argument;
 
-    /* open display */
+    /* try to open display */
     if (!(dpy = XOpenDisplay(0x0))) {
         fprintf(stderr, "Cannot open display!\n");
         exit(1);
     }
 
-    /* return status every second */	
-	for (;;) {
-		sprintf(status, FORMATSTRING, ARGUMENTS);
-		setstatus(status);
-	}
+    /* return status every interval */
+    for (;;) {
+        /* clear the string */
+        memset(status_string, 0, sizeof(status_string));
+
+        /* generate status_string */
+        for (size_t i = 0; i < sizeof(args) / sizeof(args[0]); ++i) {
+            argument = args[i];
+            char *res = argument.func(argument.args);
+            char *element = smprintf(argument.format, res);
+            strcat(status_string, element);
+            free(res);
+            free(element);
+        }
+
+        /* return the statusbar */
+        setstatus(status_string);
+
+        /* wait, "update_interval - 1" because of get_cpu_usage() which uses 1 second */
+        sleep(update_interval -1);
+    }
 
     /* close display */
     XCloseDisplay(dpy);
 
     /* exit successfully */
-	return 0;
+    return 0;
 }