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/* Copyright (C) 2017 June McEnroe <june@causal.agency>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <sys/types.h>
#include <err.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys/event.h>
#include <sys/wait.h>
#include <sysexits.h>
#include <unistd.h>
static int watch(int kq, char *path) {
int fd = open(path, O_CLOEXEC);
if (fd < 0) err(EX_NOINPUT, "%s", path);
struct kevent event;
EV_SET(
&event,
fd,
EVFILT_VNODE,
EV_ADD | EV_CLEAR,
NOTE_WRITE | NOTE_DELETE,
0,
path
);
int nevents = kevent(kq, &event, 1, NULL, 0, NULL);
if (nevents < 0) err(EX_OSERR, "kevent");
return fd;
}
static void exec(int fd, char *const argv[]) {
pid_t pid = fork();
if (pid < 0) err(EX_OSERR, "fork");
if (!pid) {
dup2(fd, STDIN_FILENO);
execvp(*argv, argv);
err(EX_NOINPUT, "%s", *argv);
}
int status;
pid = wait(&status);
if (pid < 0) err(EX_OSERR, "wait");
if (WIFEXITED(status)) {
warnx("exit %d\n", WEXITSTATUS(status));
} else if (WIFSIGNALED(status)) {
warnx("signal %d\n", WTERMSIG(status));
} else {
warnx("status %d\n", status);
}
}
int main(int argc, char *argv[]) {
bool input = false;
for (int opt; 0 < (opt = getopt(argc, argv, "i"));) {
switch (opt) {
break; case 'i': input = true;
break; default: return EX_USAGE;
}
}
argc -= optind;
argv += optind;
if (argc < 2) return EX_USAGE;
int kq = kqueue();
if (kq < 0) err(EX_OSERR, "kqueue");
int i;
for (i = 0; i < argc - 1; ++i) {
if (argv[i][0] == '-') {
i++;
break;
}
watch(kq, argv[i]);
}
if (!input) {
exec(STDIN_FILENO, &argv[i]);
}
for (;;) {
struct kevent event;
int nevents = kevent(kq, NULL, 0, &event, 1, NULL);
if (nevents < 0) err(EX_OSERR, "kevent");
if (event.fflags & NOTE_DELETE) {
close(event.ident);
sleep(1);
event.ident = watch(kq, (char *)event.udata);
} else if (input) {
off_t off = lseek(event.ident, 0, SEEK_SET);
if (off < 0) err(EX_IOERR, "lseek");
}
exec((input ? event.ident : STDIN_FILENO), &argv[i]);
}
}
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