Added README file.

[dwm-status] / dwmstatus.c

/*
* SGK version of dwmstatus by 20h.
*/

#define _BSD_SOURCE
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <time.h>
#include <X11/Xlib.h>

static Display *dpy;

char *
smprintf(char *fmt, ...)
{
       va_list fmtargs;
       char *ret;
       int len;

       va_start(fmtargs, fmt);
       len = vsnprintf(NULL, 0, fmt, fmtargs);
       va_end(fmtargs);

       ret = malloc(++len);
       if (ret == NULL) {
               perror("malloc");
               exit(1);
       }

       va_start(fmtargs, fmt);
       vsnprintf(ret, len, fmt, fmtargs);
       va_end(fmtargs);

       return ret;
}

char *
mktimes(char *fmt, char *tzname)
{
       char buf[129];
       time_t tim;
       struct tm *timtm;

       setenv("TZ", tzname, 1);
       tim = time(NULL);
       timtm = localtime(&tim);
       if (timtm == NULL)
               return smprintf("");

       if (!strftime(buf, sizeof(buf)-1, fmt, timtm)) {
               fprintf(stderr, "strftime == 0\n");
               return smprintf("");
       }

       return smprintf("%s", buf);
}

void
setstatus(char *str)
{
       XStoreName(dpy, DefaultRootWindow(dpy), str);
       XSync(dpy, False);
}

char *
loadavg(void)
{
       double avgs[3];

       if (getloadavg(avgs, 3) < 0)
               return smprintf("");

       return smprintf("%.2f", avgs[0]);
}

int
main(void)
{
       char *load, *datetime, *status;

       if (!(dpy = XOpenDisplay(NULL))) {
               fprintf(stderr, "dwmstatus: cannot open display.\n");
               return 1;
       }

       for (;;sleep(5)) {
               load = loadavg();
               datetime = mktimes("%a %d %b %Y ][ %H:%M", "America/Los_Angeles");

               status = smprintf("[ %s ][ %s ]", load, datetime);
               setstatus(status);

               free(load);
               free(datetime);
               free(status);
       }

       XCloseDisplay(dpy);

       return 0;
}