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 "slstatus.h"
  14 #include "util.h"
  15
  16 struct arg {
  17         const char *(*func)();
  18         const char *fmt;
  19         const char *args;
  20 };
  21
  22 char *argv0;
  23 char buf[1024];
  24 static unsigned short int done;
  25 static Display *dpy;
  26
  27 #include "config.h"
  28
  29 static void
  30 terminate(const int signo)
  31 {
  32         (void)signo;
  33
  34         done = 1;
  35 }
  36
  37 static void
  38 difftimespec(struct timespec *res, struct timespec *a, struct timespec *b)
  39 {
  40         res->tv_sec = a->tv_sec - b->tv_sec - (a->tv_nsec < b->tv_nsec);
  41         res->tv_nsec = a->tv_nsec - b->tv_nsec +
  42                        (a->tv_nsec < b->tv_nsec) * 1000000000;
  43 }
  44
  45 static void
  46 usage(void)
  47 {
  48         fprintf(stderr, "usage: %s [-s]\n", argv0);
  49         exit(1);
  50 }
  51
  52 int
  53 main(int argc, char *argv[])
  54 {
  55         struct sigaction act;
  56         struct timespec start, current, diff, intspec, wait;
  57         size_t i, len;
  58         int sflag = 0;
  59         char status[MAXLEN];
  60
  61         ARGBEGIN {
  62                 case 's':
  63                         sflag = 1;
  64                         break;
  65                 default:
  66                         usage();
  67         } ARGEND
  68
  69         if (argc) {
  70                 usage();
  71         }
  72
  73         setlocale(LC_ALL, "");
  74
  75         memset(&act, 0, sizeof(act));
  76         act.sa_handler = terminate;
  77         sigaction(SIGINT,  &act, NULL);
  78         sigaction(SIGTERM, &act, NULL);
  79
  80         if (!sflag && !(dpy = XOpenDisplay(NULL))) {
  81                 fprintf(stderr, "slstatus: cannot open display");
  82                 return 1;
  83         }
  84
  85         while (!done) {
  86                 clock_gettime(CLOCK_MONOTONIC, &start);
  87
  88                 status[0] = '\0';
  89                 for (i = len = 0; i < LEN(args); i++) {
  90                         const char * res = args[i].func(args[i].args);
  91                         res = (res == NULL) ? unknown_str : res;
  92                         len += snprintf(status + len, sizeof(status) - len,
  93                                         args[i].fmt, res);
  94
  95                         if (len >= sizeof(status)) {
  96                                 status[sizeof(status) - 1] = '\0';
  97                         }
  98                 }
  99
 100                 if (sflag) {
 101                         printf("%s\n", status);
 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 }