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/*
* Copyright (C) 2020 - Vito Caputo - <vcaputo@pengaru.com>
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3 as published
* by the Free Software Foundation.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
int n = argc;
struct pollfd *pfds;
assert(argc >= 1);
pfds = calloc(n, sizeof(*pfds));
if (!pfds) {
fprintf(stderr, "Unable to allocate struct pollfd array: %s\n",
strerror(errno));
return EXIT_FAILURE;
}
for (int i = 0; i < n; i++) {
if (i > 0) {
const char *path = argv[i];
pfds[i].fd = open(path, O_RDONLY);
if (pfds[i].fd == -1) {
fprintf(stderr, "Unable to open \"%s\": %s\n",
path, strerror(errno));
return EXIT_FAILURE;
}
}
pfds[i].events = POLLIN;
}
while (poll(pfds, n, -1) > 0) {
for (int i = 0; i < n; i++) {
char buf[PIPE_BUF];
ssize_t rr, rw;
if (pfds[i].revents & POLLHUP) {
fprintf(stderr, "fd %i hangup, quitting\n",
pfds[i].fd);
return EXIT_SUCCESS;
}
if (!(pfds[i].revents & POLLIN))
continue;
rr = read(pfds[i].fd, buf, sizeof(buf));
if (rr < 0) {
fprintf(stderr, "Error reading fd %i: %s\n",
pfds[i].fd, strerror(errno));
return EXIT_FAILURE;
}
rw = write(1, buf, rr);
if (rw < 0) {
fprintf(stderr, "Error writing: %s\n",
strerror(errno));
return EXIT_FAILURE;
}
if (rw != rr) {
fprintf(stderr, "Short write\n");
return EXIT_FAILURE;
}
}
}
return EXIT_FAILURE;
}
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