Refactor main()

[slstatus.git] / slstatus.c

diff --git a/slstatus.c b/slstatus.c
index cd6cc8f..cc6174a 100644 (file)
--- a/slstatus.c
+++ b/slstatus.c
@@ -5,7 +5,6 @@
 #include <ifaddrs.h>
 #include <limits.h>
 #include <linux/wireless.h>
-#include <locale.h>
 #include <netdb.h>
 #include <pwd.h>
 #include <signal.h>
@@ -71,7 +70,6 @@ static const char *wifi_perc(const char *iface);
 static const char *wifi_essid(const char *iface);
 
 char *argv0;
-static unsigned short int delay = 0;
 static unsigned short int done;
 static Display *dpy;
 
@@ -196,6 +194,7 @@ cpu_freq(void)
 static const char *
 cpu_perc(void)
 {
+       struct timespec delay;
        int n, perc;
        long double a[4], b[4];
        FILE *fp;
@@ -210,8 +209,9 @@ cpu_perc(void)
        if (n != 4)
                return unknown_str;
 
-       delay++;
-       sleep(delay);
+       delay.tv_sec = (interval / 2) / 1000;
+       delay.tv_nsec = ((interval / 2) % 1000) * 1000000;
+       nanosleep(&delay, NULL);
 
        fp = fopen("/proc/stat", "r");
        if (fp == NULL) {
@@ -842,6 +842,14 @@ terminate(const int signo)
        done = 1;
 }
 
+static void
+difftimespec(struct timespec *res, struct timespec *a, struct timespec *b)
+{
+       res->tv_sec = a->tv_sec - b->tv_sec - (a->tv_nsec < b->tv_nsec);
+       res->tv_nsec = a->tv_nsec - b->tv_nsec +
+                      (a->tv_nsec < b->tv_nsec) * 1000000000;
+}
+
 static void
 usage(void)
 {
@@ -852,12 +860,11 @@ usage(void)
 int
 main(int argc, char *argv[])
 {
-       struct arg argument;
        struct sigaction act;
+       struct timespec start, current, diff, intspec, wait;
        size_t i, len;
        int sflag = 0;
-       char status_string[MAXLEN];
-       char *element;
+       char status[MAXLEN];
 
        ARGBEGIN {
                case 's':
@@ -876,44 +883,42 @@ main(int argc, char *argv[])
        sigaction(SIGINT,  &act, NULL);
        sigaction(SIGTERM, &act, NULL);
 
-       if (!sflag) {
-               dpy = XOpenDisplay(NULL);
-               if (!dpy) {
-                       fprintf(stderr, "slstatus: cannot open display");
-                       exit(1);
-               }
+       if (!sflag && !(dpy = XOpenDisplay(NULL))) {
+               fprintf(stderr, "slstatus: cannot open display");
+               return 1;
        }
 
-       setlocale(LC_ALL, "");
-
        while (!done) {
-               status_string[0] = '\0';
-
-               for (element = status_string, i = len = 0; i < LEN(args);
-                    ++i, element += len) {
-                       argument = args[i];
-                       len = snprintf(element, sizeof(status_string)-1 - len,
-                                      argument.fmt,
-                                      argument.func(argument.args));
-                       if (len >= sizeof(status_string)) {
-                               status_string[sizeof(status_string)-1] = '\0';
-                               break;
+               clock_gettime(CLOCK_MONOTONIC, &start);
+
+               status[0] = '\0';
+               for (i = len = 0; i < LEN(args); i++) {
+                       len += snprintf(status + len, sizeof(status) - len,
+                                       args[i].fmt, args[i].func(args[i].args));
+
+                       if (len >= sizeof(status)) {
+                               status[sizeof(status) - 1] = '\0';
                        }
                }
 
                if (sflag) {
-                       printf("%s\n", status_string);
+                       printf("%s\n", status);
                } else {
-                       XStoreName(dpy, DefaultRootWindow(dpy), status_string);
+                       XStoreName(dpy, DefaultRootWindow(dpy), status);
                        XSync(dpy, False);
                }
 
-               if ((update_interval - delay) <= 0) {
-                       delay = 0;
-                       continue;
-               } else {
-                       sleep(update_interval - delay);
-                       delay = 0;
+               if (!done) {
+                       clock_gettime(CLOCK_MONOTONIC, &current);
+                       difftimespec(&diff, &current, &start);
+
+                       intspec.tv_sec = interval / 1000;
+                       intspec.tv_nsec = (interval % 1000) * 1000000;
+                       difftimespec(&wait, &intspec, &diff);
+
+                       if (wait.tv_sec >= 0) {
+                               nanosleep(&wait, NULL);
+                       }
                }
        }