X-Git-Url: https://git.xinqibao.xyz/slstatus.git/blobdiff_plain/3b6f51f8eb8f2f62b8817bb0cf654b7c77582ce7..9078fb351dc3d1e2eac261ec185acef1f66180bc:/slstatus.c

diff --git a/slstatus.c b/slstatus.c
index 467d32e..4b69cc6 100644
--- a/slstatus.c
+++ b/slstatus.c
@@ -2,362 +2,698 @@
 
 /* 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 libraries */
+/* local headers */
+#include "slstatus.h"
 #include "config.h"
 
-/* functions */
-void setstatus(char *str);
-char *battery();
-char *cpu_temperature();
-char *cpu_usage();
-char *datetime();
-char *ram_usage();
-char *smprintf(char *fmt, ...);
-char *volume();
-char *wifi_signal();
-
-/* global variables */
-static Display *dpy;
-
-/* set statusbar (WM_NAME) */
+/* set statusbar */
 void
-setstatus(char *str)
+setstatus(const char *str)
 {
-  XStoreName(dpy, DefaultRootWindow(dpy), str);
-  XSync(dpy, False);
+    /* set WM_NAME via X11 */
+    XStoreName(dpy, DefaultRootWindow(dpy), str);
+    XSync(dpy, False);
+}
+
+/* smprintf function */
+char *
+smprintf(const char *fmt, ...)
+{
+    va_list fmtargs;
+    char *ret = NULL;
+
+    va_start(fmtargs, fmt);
+    if (vasprintf(&ret, fmt, fmtargs) < 0)
+        return NULL;
+    va_end(fmtargs);
+
+    return ret;
 }
 
 /* battery percentage */
 char *
-battery()
+battery_perc(const char *battery)
+{
+    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");
+    }
+
+    /* read value */
+    fscanf(fp, "%i", &full);
+
+    /* close battery full file */
+    fclose(fp);
+
+    /* calculate percent */
+    perc = now / (full / 100);
+
+    /* return perc as string */
+    return smprintf("%d%%", perc);
+}
+
+/* cpu percentage */
+char *
+cpu_perc(const char *null)
 {
-  int battery_now, battery_full, battery_perc;
-  FILE *fp;
+    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]);
 
-  /* open battery now file */
-  if (!(fp = fopen(batterynowfile, "r"))) {
-    fprintf(stderr, "Error opening battery file.");
-    exit(1);
-  }
+    /* close stat file */
+    fclose(fp);
 
-  /* read value */
-  fscanf(fp, "%i", &battery_now);
+    /* wait a second (for avg values) */
+    sleep(1);
 
-  /* close battery now file */
-  fclose(fp);
+    /* open stat file */
+    if (!(fp = fopen("/proc/stat","r"))) {
+        fprintf(stderr, "Error opening stat file.");
+        return smprintf("n/a");
+    }
 
-  /* open battery full file */
-  if (!(fp = fopen(batteryfullfile, "r"))) {
-    fprintf(stderr, "Error opening battery file.");
-    exit(1);
-  }
+    /* read values */
+    fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2], &b[3]);
 
-  /* read value */
-  fscanf(fp, "%i", &battery_full);
+    /* 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);
+}
+
+/* date and time */
+char *
+datetime(const char *timeformat)
+{
+    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;
+}
 
-  /* close battery full file */
-  fclose(fp);
+/* disk free */
+char *
+disk_free(const char *mountpoint)
+{
+    struct statvfs fs;
 
-  /* calculate percent */
-  battery_perc = battery_now / (battery_full / 100);
+    /* try to open mountpoint */
+    if (statvfs(mountpoint, &fs) < 0) {
+        fprintf(stderr, "Could not get filesystem info.\n");
+        return smprintf("n/a");
+    }
 
-  /* return batt_perc as string */
-  return smprintf("%d%%", battery_perc);
+    /* return free */
+    return smprintf("%f", (float)fs.f_bsize * (float)fs.f_bfree / 1024 / 1024 / 1024);
 }
 
-/* cpu temperature */
+/* disk usage percentage */
 char *
-cpu_temperature()
+disk_perc(const char *mountpoint)
 {
-  int temperature;
-  FILE *fp;
+    int perc = 0;
+    struct statvfs fs;
+
+    /* try to open mountpoint */
+    if (statvfs(mountpoint, &fs) < 0) {
+        fprintf(stderr, "Could not get filesystem info.\n");
+        return smprintf("n/a");
+    }
 
-  /* open temperature file */
-  if (!(fp = fopen(tempfile, "r"))) {
-    fprintf(stderr, "Could not open temperature file.\n");
-    exit(1);
-  }
+    /* calculate percent */
+    perc = 100 * (1.0f - ((float)fs.f_bfree / (float)fs.f_blocks));
 
-  /* extract temperature */
-  fscanf(fp, "%d", &temperature);
+    /* return perc */
+    return smprintf("%d%%", perc);
+}
 
-  /* close temperature file */
-  fclose(fp);
+/* disk total */
+char *
+disk_total(const char *mountpoint)
+{
+    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");
+    }
+
+    /* return total */
+    return smprintf("%f", (float)fs.f_bsize * (float)fs.f_blocks / 1024 / 1024 / 1024);
 }
 
-/* cpu percentage */
+/* disk used */
 char *
-cpu_usage()
+disk_used(const char *mountpoint)
 {
-  int cpu_perc;
-  long double a[4], b[4];
-  FILE *fp;
+    struct statvfs fs;
 
-  /* open stat file */
-  if (!(fp = fopen("/proc/stat","r"))) {
-    fprintf(stderr, "Error opening stat 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 values */
-  fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2], &a[3]);
+    /* 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;
 
-  /* close stat file */
-  fclose(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");
+    }
 
-  /* wait a second (for avg values) */
-  sleep(1);
+    /* extract entropy */
+    fscanf(fp, "%d", &entropy);
 
-  /* open stat file */
-  if (!(fp = fopen("/proc/stat","r"))) {
-    fprintf(stderr, "Error opening stat file.");
-    exit(1);
-  }
+    /* close entropy file */
+    fclose(fp);
 
-  /* read values */
-  fscanf(fp, "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2], &b[3]);
+    /* return entropy */
+    return smprintf("%d", entropy);
+}
 
-  /* close stat file */
-  fclose(fp);
+/* gid */
+char *
+gid(const char *null)
+{
+    gid_t gid;
 
-  /* 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]));
+    if ((gid = getgid()) < 0) {
+        fprintf(stderr, "Could no get gid.");
+        return smprintf("n/a");
+    } else {
+        return smprintf("%d", gid);
+    }
 
-  /* return cpu_perc as string */
-  return smprintf("%d%%", cpu_perc);
+    return smprintf("n/a");
 }
 
-/* date and time */
+/* hostname */
+char *
+hostname(const char *null)
+{
+    char hostname[HOST_NAME_MAX];
+    FILE *fp;
+
+    /* open hostname file */
+    if (!(fp = fopen("/proc/sys/kernel/hostname", "r"))) {
+        fprintf(stderr, "Could not open hostname file.\n");
+        return smprintf("n/a");
+    }
+
+    /* extract hostname */
+    fscanf(fp, "%s\n", hostname);
+
+    /* close hostname file */
+    fclose(fp);
+
+    /* return entropy */
+    return smprintf("%s", hostname);
+}
+
+/* ip address */
 char *
-datetime()
+ip(const char *interface)
 {
-  time_t tm;
-  size_t bufsize = 19;
-  char *buf = malloc(bufsize);
-
-  /* get time in format */
-  time(&tm);
-  if(!strftime(buf, bufsize, timeformat, localtime(&tm))) {
-    fprintf(stderr, "Strftime failed.\n");
-    exit(1);
-  }
-
-  /* return time */
-  return buf;
+    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 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);
+        }
+    }
+
+    /* free the address */
+    freeifaddrs(ifaddr);
+
+    /* return n/a if nothing works */
+    return smprintf("n/a");
+}
+
+/* ram free */
+char *
+ram_free(const char *null)
+{
+    long free;
+    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: %*d kB\n");
+    fscanf(fp, "MemFree: %ld kB\n", &free);
+
+    /* close meminfo file */
+    fclose(fp);
+
+    /* return free ram as string */
+    return smprintf("%f", (float)free / 1024 / 1024);
 }
 
 /* ram percentage */
 char *
-ram_usage()
+ram_perc(const char *null)
 {
-  int ram_perc;
-  long total, free, available;
-  FILE *fp;
+    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 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 meminfo file */
+    fclose(fp);
+
+    /* calculate percentage */
+    perc = 100 * ((total - free) - (buffers + cached)) / total;
+
+    /* return perc as string */
+    return smprintf("%d%%", perc);
+}
 
-  /* open meminfo file */
-  if (!(fp = fopen("/proc/meminfo", "r"))) {
-    fprintf(stderr, "Error opening meminfo file.");
-    exit(1);
-  }
+/* ram total */
+char *
+ram_total(const char *null)
+{
+    long total;
+    FILE *fp;
 
-  /* read the values */
-  fscanf(fp, "MemTotal: %ld kB\n", &total);
-  fscanf(fp, "MemFree: %ld kB\n", &free);
-  fscanf(fp, "MemAvailable: %ld kB\n", &available);
+    /* open meminfo file */
+    if (!(fp = fopen("/proc/meminfo", "r"))) {
+        fprintf(stderr, "Error opening meminfo file.");
+        return smprintf("n/a");
+    }
 
-  /* close meminfo file */
-  fclose(fp);
+    /* read the values */
+    fscanf(fp, "MemTotal: %ld kB\n", &total);
 
-  /* calculate percentage */
-  ram_perc = 100 * (total - available) / total;
+    /* close meminfo file */
+    fclose(fp);
 
-  /* return ram_perc as string */
-  return smprintf("%d%%",ram_perc);
+    /* return total ram as string */
+    return smprintf("%f", (float)total / 1024 / 1024);
 }
 
-/* smprintf function */
+/* 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\nBuffers: %ld kB\n", &buffers, &buffers);
+    fscanf(fp, "Cached: %ld kB\n", &cached);
+
+    /* close meminfo file */
+    fclose(fp);
+
+    /* 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");
+    }
+
+    /* 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 *
-smprintf(char *fmt, ...)
+username(const char *null)
 {
-  va_list fmtargs;
-  char *ret;
-  int len;
+    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");
+}
 
-  va_start(fmtargs, fmt);
-  len = vsnprintf(NULL, 0, fmt, fmtargs);
-  va_end(fmtargs);
+/* uid */
+char *
+uid(const char *null)
+{
+    register uid_t uid;
 
-  ret = malloc(++len);
-  if (ret == NULL) {
-    fprintf(stderr, "Malloc error.");
-    exit(1);
-  }
+    /* get the values */
+    uid = geteuid ();
 
-  va_start(fmtargs, fmt);
-  vsnprintf(ret, len, fmt, fmtargs);
-  va_end(fmtargs);
+    /* if it worked, return */
+    if (uid) {
+        return smprintf("%d", uid);
+    }
+    else {
+        fprintf(stderr, "Could not get uid.\n");
+        return smprintf("n/a");
+    }
 
-  return ret;
+    return smprintf("n/a");
 }
 
+
 /* alsa volume percentage */
 char *
-volume()
+vol_perc(const char *soundcard)
 {
-  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 smprintf("mute");
-  else
-    return smprintf("%d%%", (vol * 100) / max);
+    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_signal()
+wifi_perc(const char *wificard)
 {
-  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];
-  char needle[sizeof wificard + 1];
-  FILE *fp;
-
-  /* generate the path name */
-
-  memset(path, 0, sizeof path);
-  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);
-  }
-
-  /* read the status */
-  fgets(status, 5, fp);
-
-  /* close wifi file */
-  fclose(fp);
-
-  /* check if interface down */
-  if(strcmp(status, "up\n") != 0){
-    return "n/a";
-  }
-
-  /* open wifi file */
-  if (!(fp = fopen("/proc/net/wireless", "r"))) {
-    fprintf(stderr, "Error opening wireless file.");
-    exit(1);
-  }
-
-  /* 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);
+    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];
-
-  /* open display */
-  if (!(dpy = XOpenDisplay(0x0))) {
-    fprintf(stderr, "Cannot open display!\n");
-    exit(1);
-  }
-
-  char *pWifi_signal = NULL;
-  char *pBattery = NULL;
-  char *pCpu_usage = NULL;
-  char *pCpu_temperature = NULL;
-  char *pRam_usage = NULL;
-  char *pVolume = NULL;
-  char *pDatetime = NULL;
-
-  /* return status every second */
-  for (;;) {
-    pWifi_signal = wifi_signal();
-    pBattery = battery();
-    pCpu_usage = cpu_usage();
-    pCpu_temperature = cpu_temperature();
-    pRam_usage = ram_usage();
-    pVolume = volume();
-    pDatetime = datetime();
-    sprintf(status, FORMATSTRING, ARGUMENTS);
-    setstatus(status);
-    free(pWifi_signal);
-    free(pBattery);
-    free(pCpu_usage);
-    free(pCpu_temperature);
-    free(pRam_usage);
-    free(pVolume);
-    free(pDatetime);
-  }
-
-  /* close display */
-  XCloseDisplay(dpy);
-
-  /* exit successfully */
-  return 0;
+    char status_string[1024];
+    struct arg argument;
+
+    /* try to open display */
+    if (!(dpy = XOpenDisplay(0x0))) {
+        fprintf(stderr, "Cannot open display!\n");
+        exit(1);
+    }
+
+    /* 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;
 }