slstatus/slstatus.c
2025-03-12 08:38:50 -06:00

137 lines
2.7 KiB
C

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "arg.h"
#include "slstatus.h"
#include "util.h"
struct arg {
const char *(*func)(const char *);
const char *fmt;
const char *args;
unsigned int turn;
int signal;
};
char buf[1024];
static volatile sig_atomic_t done, upsigno;
#include "config.h"
#define MAXLEN CMDLEN * LEN(args)
static char statuses[LEN(args)][CMDLEN] = {0};
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) * 1E9;
}
static void
usage(void)
{
die("usage: %s [-v] [-s] [-1]", argv0);
}
static void
printstatus(unsigned int iter)
{
size_t i;
char status[MAXLEN];
const char *res;
for (i = 0; i < LEN(args); i++) {
if (!((!iter && !upsigno) || upsigno == SIGUSR1 ||
(!upsigno && args[i].turn > 0 && !(iter % args[i].turn)) ||
(args[i].signal >= 0 && upsigno - SIGRTMIN == args[i].signal)))
continue;
if (!(res = args[i].func(args[i].args)))
res = unknown_str;
if (esnprintf(statuses[i], sizeof(statuses[i]), args[i].fmt, res) < 0)
break;
}
status[0] = '\0';
for (i = 0; i < LEN(args); i++)
strcat(status, statuses[i]);
status[strlen(status)] = '\0';
puts(status);
fflush(stdout);
if (ferror(stdout))
die("puts:");
}
static void
sighandler(const int signo)
{
if ((signo <= SIGRTMAX && signo >= SIGRTMIN) || signo == SIGUSR1)
upsigno = signo;
else
done = 1;
}
int
main(int argc, char *argv[])
{
struct sigaction act;
struct timespec start, current, diff, intspec, wait;
unsigned int iter = 0;
int i, ret;
ARGBEGIN {
case 'v':
die("slstatus-"VERSION);
default:
usage();
} ARGEND
if (argc)
usage();
memset(&act, 0, sizeof(act));
act.sa_handler = sighandler;
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
sigaction(SIGUSR1, &act, NULL);
for (i = SIGRTMIN; i <= SIGRTMAX; i++)
sigaction(i, &act, NULL);
do {
if (clock_gettime(CLOCK_MONOTONIC, &start) < 0)
die("clock_gettime:");
printstatus(iter++);
if (!done) {
if (clock_gettime(CLOCK_MONOTONIC, &current) < 0)
die("clock_gettime:");
difftimespec(&diff, &current, &start);
intspec.tv_sec = interval / 1000;
intspec.tv_nsec = (interval % 1000) * 1E6;
difftimespec(&wait, &intspec, &diff);
while(wait.tv_sec >= 0 &&
(ret = nanosleep(&wait, &wait)) < 0 &&
errno == EINTR && !done) {
printstatus(0);
errno = upsigno = 0;
}
if (ret < 0 && errno != EINTR)
die("nanosleep:");
}
} while (!done);
return 0;
}