ladybird/Userland/Utilities/tee.cpp

111 lines
3.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2022, Kenneth Myhra <kennethmyhra@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Vector.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/stat.h>
#include <unistd.h>
static ErrorOr<Vector<int>> collect_fds(Vector<StringView> paths, bool append)
{
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;
TRY(fds.try_ensure_capacity(paths.size() + 1));
for (auto path : paths) {
int fd = TRY(Core::System::open(path, oflag, mode));
fds.unchecked_append(fd);
}
fds.unchecked_append(STDOUT_FILENO);
return fds;
}
static ErrorOr<void> copy_stdin(Vector<int>& fds, bool* err)
{
for (;;) {
Array<u8, 4096> buffer;
auto buffer_span = buffer.span();
auto nread = TRY(Core::System::read(STDIN_FILENO, buffer_span));
buffer_span = buffer_span.trim(nread);
if (nread == 0)
break;
Vector<int> broken_fds;
for (size_t i = 0; i < fds.size(); ++i) {
auto fd = fds.at(i);
auto nwrite_or_error = Core::System::write(fd, buffer_span);
if (nwrite_or_error.is_error()) {
if (nwrite_or_error.error().code() == EINTR) {
continue;
} else {
warnln("{}", nwrite_or_error.release_error());
*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;
}
}
}
// 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; });
}
return {};
}
static ErrorOr<void> close_fds(Vector<int>& fds)
{
for (int fd : fds)
TRY(Core::System::close(fd));
return {};
}
static void int_handler(int)
{
// pass
}
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
bool append = false;
bool ignore_interrupts = false;
Vector<StringView> 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(arguments);
if (ignore_interrupts)
TRY(Core::System::signal(SIGINT, int_handler));
auto fds = TRY(collect_fds(paths, append));
bool err_write = false;
TRY(copy_stdin(fds, &err_write));
TRY(close_fds(fds));
return err_write ? 1 : 0;
}