slstatus.c

   1 /* See LICENSE file for copyright and license details. */
   2 #include <err.h>
   3 #include <errno.h>
   4 #include <locale.h>
   5 #include <signal.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <time.h>
  10 #include <X11/Xlib.h>
  11
  12 #include "arg.h"
  13 #include "util.h"
  14
  15 struct arg {
  16         const char *(*func)();
  17         const char *fmt;
  18         const char *args;
  19 };
  20
  21 char *argv0;
  22 static unsigned short int done;
  23 static Display *dpy;
  24
  25 #include "slstatus.h"
  26 #include "config.h"
  27
  28 static void
  29 terminate(const int signo)
  30 {
  31         done = 1;
  32 }
  33
  34 static void
  35 difftimespec(struct timespec *res, struct timespec *a, struct timespec *b)
  36 {
  37         res->tv_sec = a->tv_sec - b->tv_sec - (a->tv_nsec < b->tv_nsec);
  38         res->tv_nsec = a->tv_nsec - b->tv_nsec +
  39                        (a->tv_nsec < b->tv_nsec) * 1000000000;
  40 }
  41
  42 static void
  43 usage(void)
  44 {
  45         fprintf(stderr, "usage: %s [-s]\n", argv0);
  46         exit(1);
  47 }
  48
  49 int
  50 main(int argc, char *argv[])
  51 {
  52         struct sigaction act;
  53         struct timespec start, current, diff, intspec, wait;
  54         size_t i, len;
  55         int sflag = 0;
  56         char status[MAXLEN];
  57
  58         ARGBEGIN {
  59                 case 's':
  60                         sflag = 1;
  61                         break;
  62                 default:
  63                         usage();
  64         } ARGEND
  65
  66         if (argc) {
  67                 usage();
  68         }
  69
  70         setlocale(LC_ALL, "");
  71
  72         memset(&act, 0, sizeof(act));
  73         act.sa_handler = terminate;
  74         sigaction(SIGINT,  &act, NULL);
  75         sigaction(SIGTERM, &act, NULL);
  76
  77         if (!sflag && !(dpy = XOpenDisplay(NULL))) {
  78                 fprintf(stderr, "slstatus: cannot open display");
  79                 return 1;
  80         }
  81
  82         while (!done) {
  83                 clock_gettime(CLOCK_MONOTONIC, &start);
  84
  85                 status[0] = '\0';
  86                 for (i = len = 0; i < LEN(args); i++) {
  87                         len += snprintf(status + len, sizeof(status) - len,
  88                                         args[i].fmt, args[i].func(args[i].args));
  89
  90                         if (len >= sizeof(status)) {
  91                                 status[sizeof(status) - 1] = '\0';
  92                         }
  93                 }
  94
  95                 if (sflag) {
  96                         printf("%s\n", status);
  97                 } else {
  98                         XStoreName(dpy, DefaultRootWindow(dpy), status);
  99                         XSync(dpy, False);
 100                 }
 101
 102                 if (!done) {
 103                         clock_gettime(CLOCK_MONOTONIC, &current);
 104                         difftimespec(&diff, &current, &start);
 105
 106                         intspec.tv_sec = interval / 1000;
 107                         intspec.tv_nsec = (interval % 1000) * 1000000;
 108                         difftimespec(&wait, &intspec, &diff);
 109
 110                         if (wait.tv_sec >= 0) {
 111                                 nanosleep(&wait, NULL);
 112                         }
 113                 }
 114         }
 115
 116         if (!sflag) {
 117                 XStoreName(dpy, DefaultRootWindow(dpy), NULL);
 118                 XCloseDisplay(dpy);
 119         }
 120
 121         return 0;
 122 }