Dwmstatus/dwmstatus.c
2024-02-04 21:22:56 -03:00

164 lines
2.6 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <sys/select.h>
#include <sys/fcntl.h>
#include <sys/wait.h>
typedef struct Process Process;
struct Process {
pid_t pid;
int fd;
char str[64];
Process *next;
};
static Process *list = NULL;
int
max(int a, int b)
{
return (a > b ? a : b);
}
Process *
newproc(const char *command)
{
Process *p;
int pipes[2];
pid_t pid;
if(pipe(pipes) < 0) {
perror("pipe()");
exit(EXIT_FAILURE);
}
switch((pid = fork())) {
case -1:
perror("fork()");
exit(EXIT_FAILURE);
case 0:
close(0);
close(1);
dup2(pipes[1], 1);
close(pipes[0]);
close(pipes[1]);
execl("/bin/sh", "/bin/sh", "-c", command, NULL);
exit(EXIT_SUCCESS);
return NULL;
default:
close(pipes[1]);
p = malloc(sizeof *p);
if(!p) {
perror("malloc()");
exit(EXIT_FAILURE);
}
memset(p, 0, sizeof *p);
p->pid = pid;
p->fd = pipes[0];
return p;
}
}
static void
sigtrap(int sig)
{
if(sig != SIGINT)
return;
for(Process *p = list; p; p = p->next) {
killpg(p->pid, sig);
}
while(wait(NULL) != -1 || errno == EINTR);
/* let the operating take care of the memory leak, fuck it */
exit(EXIT_SUCCESS);
}
int
linerd(int fd, char *line, int linesize)
{
int i;
for(i = 0; i < linesize; i++) {
char c;
if(read(fd, &c, sizeof c) <= 0) {
break;
}
if(c == '\n') {
line[i] = 0;
break;
}
line[i] = c;
}
line[linesize - 1] = 0;
return i;
}
int
main(int argc, char *argv[])
{
int maxfd = 0, i, c;
fd_set rdset;
Process *p;
signal(SIGINT, sigtrap);
signal(SIGTERM, sigtrap);
signal(SIGKILL, sigtrap);
FD_ZERO(&rdset);
while((c = getopt(argc, argv, "c:")) > 0) {
switch(c) {
case 'c':
p = newproc(optarg);
FD_SET(p->fd, &rdset);
maxfd = max(maxfd, p->fd);
p->next = list;
list = p;
break;
default:
fprintf(stderr, "Unknown option: %c\n", c);
exit(EXIT_FAILURE);
}
}
if(!list) {
fprintf(stderr, "usage: %s -c command [-c command2 ]...\n", argv[0]);
exit(EXIT_FAILURE);
}
for(;;) {
int n;
fd_set copy;
FD_ZERO(&copy);
memcpy(&copy, &rdset, sizeof rdset);
n = select(maxfd + 1, &copy, NULL, NULL, NULL);
if(n < 0) {
perror("select()");
continue;
}
for(Process *p = list; p; p = p->next)
if(FD_ISSET(p->fd, &copy)) {
if(linerd(p->fd, p->str, sizeof p->str) <= 0) {
FD_CLR(p->fd, &rdset);
close(p->fd);
}
}
for(Process *p = list; p; p = p->next)
printf("%s%s", p->str, p->next ? " | " : "");
printf("\n");
fflush(stdout);
}
return 0;
}