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 unsigned short 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 = 0;
  57         char status[MAXLEN];
  58
  59         ARGBEGIN {
  60                 case 's':
  61                         sflag = 1;
  62                         break;
  63                 default:
  64                         usage();
  65         } ARGEND
  66
  67         if (argc) {
  68                 usage();
  69         }
  70
  71         setlocale(LC_ALL, "");
  72
  73         memset(&act, 0, sizeof(act));
  74         act.sa_handler = terminate;
  75         sigaction(SIGINT,  &act, NULL);
  76         sigaction(SIGTERM, &act, NULL);
  77
  78         if (!sflag && !(dpy = XOpenDisplay(NULL))) {
  79                 fprintf(stderr, "Cannot open display");
  80                 return 1;
  81         }
  82
  83         while (!done) {
  84                 clock_gettime(CLOCK_MONOTONIC, &start);
  85
  86                 status[0] = '\0';
  87                 for (i = len = 0; i < LEN(args); i++) {
  88                         const char * res = args[i].func(args[i].args);
  89                         res = (res == NULL) ? unknown_str : res;
  90                         len += snprintf(status + len, sizeof(status) - len,
  91                                         args[i].fmt, res);
  92
  93                         if (len >= sizeof(status)) {
  94                                 status[sizeof(status) - 1] = '\0';
  95                         }
  96                 }
  97
  98                 if (sflag) {
  99                         printf("%s\n", status);
 100                 } else {
 101                         XStoreName(dpy, DefaultRootWindow(dpy), status);
 102                         XSync(dpy, False);
 103                 }
 104
 105                 if (!done) {
 106                         clock_gettime(CLOCK_MONOTONIC, &current);
 107                         difftimespec(&diff, &current, &start);
 108
 109                         intspec.tv_sec = interval / 1000;
 110                         intspec.tv_nsec = (interval % 1000) * 1000000;
 111                         difftimespec(&wait, &intspec, &diff);
 112
 113                         if (wait.tv_sec >= 0) {
 114                                 nanosleep(&wait, NULL);
 115                         }
 116                 }
 117         }
 118
 119         if (!sflag) {
 120                 XStoreName(dpy, DefaultRootWindow(dpy), NULL);
 121                 XCloseDisplay(dpy);
 122         }
 123
 124         return 0;
 125 }