slstatus.c

   1 /* See LICENSE file for copyright and license details. */
   2 #include <errno.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 buf[1024];
  21 static volatile sig_atomic_t done;
  22 static Display *dpy;
  23
  24 #include "config.h"
  25
  26 static void
  27 terminate(const int signo)
  28 {
  29         if (signo != SIGUSR1)
  30                 done = 1;
  31 }
  32
  33 static void
  34 difftimespec(struct timespec *res, struct timespec *a, struct timespec *b)
  35 {
  36         res->tv_sec = a->tv_sec - b->tv_sec - (a->tv_nsec < b->tv_nsec);
  37         res->tv_nsec = a->tv_nsec - b->tv_nsec +
  38                        (a->tv_nsec < b->tv_nsec) * 1E9;
  39 }
  40
  41 static void
  42 usage(void)
  43 {
  44         die("usage: %s [-s] [-1]", argv0);
  45 }
  46
  47 int
  48 main(int argc, char *argv[])
  49 {
  50         struct sigaction act;
  51         struct timespec start, current, diff, intspec, wait;
  52         size_t i, len;
  53         int sflag, ret;
  54         char status[MAXLEN];
  55         const char *res;
  56
  57         sflag = 0;
  58         ARGBEGIN {
  59                 case '1':
  60                         done = 1;
  61                         /* fallthrough */
  62                 case 's':
  63                         sflag = 1;
  64                         break;
  65                 default:
  66                         usage();
  67         } ARGEND
  68
  69         if (argc) {
  70                 usage();
  71         }
  72
  73         memset(&act, 0, sizeof(act));
  74         act.sa_handler = terminate;
  75         sigaction(SIGINT,  &act, NULL);
  76         sigaction(SIGTERM, &act, NULL);
  77         act.sa_flags |= SA_RESTART;
  78         sigaction(SIGUSR1, &act, NULL);
  79
  80         if (!sflag && !(dpy = XOpenDisplay(NULL))) {
  81                 die("XOpenDisplay: Failed to open display");
  82         }
  83
  84         do {
  85                 if (clock_gettime(CLOCK_MONOTONIC, &start) < 0) {
  86                         die("clock_gettime:");
  87                 }
  88
  89                 status[0] = '\0';
  90                 for (i = len = 0; i < LEN(args); i++) {
  91                         if (!(res = args[i].func(args[i].args))) {
  92                                 res = unknown_str;
  93                         }
  94                         if ((ret = esnprintf(status + len, sizeof(status) - len,
  95                                             args[i].fmt, res)) < 0) {
  96                                 break;
  97                         }
  98                         len += ret;
  99                 }
 100
 101                 if (sflag) {
 102                         puts(status);
 103                         fflush(stdout);
 104                         if (ferror(stdout))
 105                                 die("puts:");
 106                 } else {
 107                         if (XStoreName(dpy, DefaultRootWindow(dpy), status)
 108                             < 0) {
 109                                 die("XStoreName: Allocation failed");
 110                         }
 111                         XFlush(dpy);
 112                 }
 113
 114                 if (!done) {
 115                         if (clock_gettime(CLOCK_MONOTONIC, &current) < 0) {
 116                                 die("clock_gettime:");
 117                         }
 118                         difftimespec(&diff, &current, &start);
 119
 120                         intspec.tv_sec = interval / 1000;
 121                         intspec.tv_nsec = (interval % 1000) * 1E6;
 122                         difftimespec(&wait, &intspec, &diff);
 123
 124                         if (wait.tv_sec >= 0) {
 125                                 if (nanosleep(&wait, NULL) < 0 &&
 126                                     errno != EINTR) {
 127                                         die("nanosleep:");
 128                                 }
 129                         }
 130                 }
 131         } while (!done);
 132
 133         if (!sflag) {
 134                 XStoreName(dpy, DefaultRootWindow(dpy), NULL);
 135                 if (XCloseDisplay(dpy) < 0) {
 136                         die("XCloseDisplay: Failed to close display");
 137                 }
 138         }
 139
 140         return 0;
 141 }