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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Vector.h>
#include <LibCore/ArgsParser.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>
static Vector<int> collect_fds(Vector<const char*> paths, bool append, bool* err)
{
int oflag;
mode_t mode;
if (append) {
oflag = O_APPEND;
mode = 0;
} else {
oflag = O_CREAT | O_WRONLY | O_TRUNC;
mode = S_IROTH | S_IWOTH | S_IRGRP | S_IWGRP | S_IRUSR | S_IWUSR;
}
Vector<int> fds;
for (const char* path : paths) {
int fd = open(path, oflag, mode);
if (fd < 0) {
perror("failed to open file for writing");
*err = true;
} else {
fds.append(fd);
}
}
fds.append(STDOUT_FILENO);
return fds;
}
static void copy_stdin(Vector<int>& fds, bool* err)
{
for (;;) {
char buf[4096];
ssize_t nread = read(STDIN_FILENO, buf, sizeof(buf));
if (nread == 0)
break;
if (nread < 0) {
perror("read() error");
*err = true;
// a failure to read from stdin should lead to an early exit
return;
}
Vector<int> broken_fds;
for (size_t i = 0; i < fds.size(); ++i) {
auto fd = fds.at(i);
int twrite = 0;
while (twrite != nread) {
ssize_t nwrite = write(fd, buf + twrite, nread - twrite);
if (nwrite < 0) {
if (errno == EINTR) {
continue;
} else {
perror("write() failed");
*err = true;
broken_fds.append(fd);
// write failures to a successfully opened fd shall
// prevent further writes, but shall not block writes
// to the other open fds
break;
}
} else {
twrite += nwrite;
}
}
}
// remove any fds which we can no longer write to for subsequent copies
for (auto to_remove : broken_fds)
fds.remove_first_matching([&](int fd) { return to_remove == fd; });
}
}
static void close_fds(Vector<int>& fds)
{
for (int fd : fds) {
int closed = close(fd);
if (closed < 0) {
perror("failed to close output file");
}
}
}
static void int_handler(int)
{
// pass
}
int main(int argc, char** argv)
{
bool append = false;
bool ignore_interrupts = false;
Vector<const char*> paths;
Core::ArgsParser args_parser;
args_parser.add_option(append, "Append, don't overwrite", "append", 'a');
args_parser.add_option(ignore_interrupts, "Ignore SIGINT", "ignore-interrupts", 'i');
args_parser.add_positional_argument(paths, "Files to copy stdin to", "file", Core::ArgsParser::Required::No);
args_parser.parse(argc, argv);
if (ignore_interrupts) {
if (signal(SIGINT, int_handler) == SIG_ERR)
perror("failed to install SIGINT handler");
}
bool err_open = false;
bool err_write = false;
auto fds = collect_fds(paths, append, &err_open);
copy_stdin(fds, &err_write);
close_fds(fds);
return (err_open || err_write) ? 1 : 0;
}
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