slstatus.c

   1 /* See LICENSE file for copyright and license details. */
   2 #include <locale.h>
   3 #include <signal.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <time.h>
   8 #include <X11/Xlib.h>
   9
  10 #include "arg.h"
  11 #include "slstatus.h"
  12 #include "util.h"
  13
  14 struct arg {
  15         const char *(*func)();
  16         const char *fmt;
  17         const char *args;
  18 };
  19
  20 char *argv0;
  21 char buf[1024];
  22 static int done;
  23 static Display *dpy;
  24
  25 #include "config.h"
  26
  27 static void
  28 terminate(const int signo)
  29 {
  30         (void)signo;
  31
  32         done = 1;
  33 }
  34
  35 static void
  36 difftimespec(struct timespec *res, struct timespec *a, struct timespec *b)
  37 {
  38         res->tv_sec = a->tv_sec - b->tv_sec - (a->tv_nsec < b->tv_nsec);
  39         res->tv_nsec = a->tv_nsec - b->tv_nsec +
  40                        (a->tv_nsec < b->tv_nsec) * 1000000000;
  41 }
  42
  43 static void
  44 usage(void)
  45 {
  46         fprintf(stderr, "usage: %s [-s]\n", argv0);
  47         exit(1);
  48 }
  49
  50 int
  51 main(int argc, char *argv[])
  52 {
  53         struct sigaction act;
  54         struct timespec start, current, diff, intspec, wait;
  55         size_t i, len;
  56         int sflag;
  57         char status[MAXLEN];
  58
  59         sflag = 0;
  60         ARGBEGIN {
  61                 case 's':
  62                         sflag = 1;
  63                         break;
  64                 default:
  65                         usage();
  66         } ARGEND
  67
  68         if (argc) {
  69                 usage();
  70         }
  71
  72         setlocale(LC_ALL, "");
  73
  74         memset(&act, 0, sizeof(act));
  75         act.sa_handler = terminate;
  76         sigaction(SIGINT,  &act, NULL);
  77         sigaction(SIGTERM, &act, NULL);
  78
  79         if (!sflag && !(dpy = XOpenDisplay(NULL))) {
  80                 fprintf(stderr, "Cannot open display");
  81                 return 1;
  82         }
  83
  84         while (!done) {
  85                 clock_gettime(CLOCK_MONOTONIC, &start);
  86
  87                 status[0] = '\0';
  88                 for (i = len = 0; i < LEN(args); i++) {
  89                         const char * res = args[i].func(args[i].args);
  90                         res = (res == NULL) ? unknown_str : res;
  91                         len += snprintf(status + len, sizeof(status) - len,
  92                                         args[i].fmt, res);
  93
  94                         if (len >= sizeof(status)) {
  95                                 status[sizeof(status) - 1] = '\0';
  96                         }
  97                 }
  98
  99                 if (sflag) {
 100                         printf("%s\n", status);
 101                         fflush(stdout);
 102                 } else {
 103                         XStoreName(dpy, DefaultRootWindow(dpy), status);
 104                         XSync(dpy, False);
 105                 }
 106
 107                 if (!done) {
 108                         clock_gettime(CLOCK_MONOTONIC, &current);
 109                         difftimespec(&diff, &current, &start);
 110
 111                         intspec.tv_sec = interval / 1000;
 112                         intspec.tv_nsec = (interval % 1000) * 1000000;
 113                         difftimespec(&wait, &intspec, &diff);
 114
 115                         if (wait.tv_sec >= 0) {
 116                                 nanosleep(&wait, NULL);
 117                         }
 118                 }
 119         }
 120
 121         if (!sflag) {
 122                 XStoreName(dpy, DefaultRootWindow(dpy), NULL);
 123                 XCloseDisplay(dpy);
 124         }
 125
 126         return 0;
 127 }