slstatus/slstatus.c
Josuah Demangeon 7e29da026b fflush(stdout) to print line by line if stdout is not a tty
To reproduce the issue:
	$ slstatus -s | tee

then it would print only when the stdout buffer is full, by block
of multiple lines.

fflush() makes sure the line is printed at every loop iteration
2018-05-08 15:18:32 +02:00

128 lines
2.3 KiB
C

/* See LICENSE file for copyright and license details. */
#include <locale.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <X11/Xlib.h>
#include "arg.h"
#include "slstatus.h"
#include "util.h"
struct arg {
const char *(*func)();
const char *fmt;
const char *args;
};
char *argv0;
char buf[1024];
static unsigned short int done;
static Display *dpy;
#include "config.h"
static void
terminate(const int signo)
{
(void)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)
{
fprintf(stderr, "usage: %s [-s]\n", argv0);
exit(1);
}
int
main(int argc, char *argv[])
{
struct sigaction act;
struct timespec start, current, diff, intspec, wait;
size_t i, len;
int sflag;
char status[MAXLEN];
sflag = 0;
ARGBEGIN {
case 's':
sflag = 1;
break;
default:
usage();
} ARGEND
if (argc) {
usage();
}
setlocale(LC_ALL, "");
memset(&act, 0, sizeof(act));
act.sa_handler = terminate;
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
if (!sflag && !(dpy = XOpenDisplay(NULL))) {
fprintf(stderr, "Cannot open display");
return 1;
}
while (!done) {
clock_gettime(CLOCK_MONOTONIC, &start);
status[0] = '\0';
for (i = len = 0; i < LEN(args); i++) {
const char * res = args[i].func(args[i].args);
res = (res == NULL) ? unknown_str : res;
len += snprintf(status + len, sizeof(status) - len,
args[i].fmt, res);
if (len >= sizeof(status)) {
status[sizeof(status) - 1] = '\0';
}
}
if (sflag) {
printf("%s\n", status);
fflush(stdout);
} else {
XStoreName(dpy, DefaultRootWindow(dpy), status);
XSync(dpy, False);
}
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);
}
}
}
if (!sflag) {
XStoreName(dpy, DefaultRootWindow(dpy), NULL);
XCloseDisplay(dpy);
}
return 0;
}