ladybird/Userland/Utilities/nohup.cpp
Kemal Zebari 590f0f85e0 nohup: Don't leak fd used to open nohup.out
Since we may redirect stdout, stderr, or both to the file description
referring to the nohup.out file, there is no need to keep the fd that
created that file description around.
2023-07-31 10:47:59 +02:00

122 lines
3.9 KiB
C++

/*
* Copyright (c) 2023, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/LexicalPath.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <stdlib.h>
#include <unistd.h>
namespace {
void dup_out_file(int fd_to_redirect)
{
int fd = -1;
DeprecatedString path = "nohup.out";
auto options = O_CREAT | O_WRONLY | O_APPEND;
auto mode = S_IRUSR | S_IWUSR;
auto fd_or_error = Core::System::open(path, options, mode);
if (fd_or_error.is_error()) {
auto* home_env = getenv("HOME");
if (!home_env) {
warnln("nohup: unable to open for appending as $HOME is not set");
exit(127);
}
path = LexicalPath::join(LexicalPath::canonicalized_path(home_env), path).string();
fd_or_error = Core::System::open(path, options, mode);
if (fd_or_error.is_error()) {
warnln("nohup: unable to open {} for appending: {}", path, strerror(fd_or_error.error().code()));
exit(127);
}
}
fd = fd_or_error.value();
auto maybe_error = Core::System::dup2(fd, fd_to_redirect);
if (maybe_error.is_error()) {
warnln("nohup: redirection failed: {}", strerror(maybe_error.error().code()));
exit(127);
}
MUST(Core::System::close(fd));
if (fd_to_redirect != STDERR_FILENO)
outln(stderr, "appending output to {}", path);
}
}
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
TRY(Core::System::pledge("stdio wpath cpath rpath exec sigaction"));
StringView utility;
Vector<StringView> args;
Core::ArgsParser args_parser;
args_parser.set_stop_on_first_non_option(true);
args_parser.set_general_help("Invoke a utility that will ignore SIGHUPs");
args_parser.add_positional_argument(utility, "Utility to be invoked", "utility");
args_parser.add_positional_argument(args, "Arguments to pass to utility", "args", Core::ArgsParser::Required::No);
args_parser.parse(arguments);
auto stdout_is_a_tty = false;
auto tty_or_error = Core::System::isatty(STDOUT_FILENO);
if (tty_or_error.is_error()) {
auto error = tty_or_error.release_error();
if (error.code() != EBADF) {
warnln("nohup: error while performing tty check on stdout: {}", strerror(error.code()));
return 127;
}
} else {
stdout_is_a_tty = tty_or_error.value();
}
if (stdout_is_a_tty)
dup_out_file(STDOUT_FILENO);
auto stderr_is_a_tty = false;
tty_or_error = Core::System::isatty(STDERR_FILENO);
if (tty_or_error.is_error()) {
auto error = tty_or_error.release_error();
if (error.code() != EBADF) {
warnln("nohup: error while performing tty check on stderr: {}", strerror(error.code()));
return 127;
}
} else {
stderr_is_a_tty = tty_or_error.value();
}
if (stderr_is_a_tty) {
auto dup_or_error = Core::System::dup2(STDOUT_FILENO, STDERR_FILENO);
if (dup_or_error.is_error()) {
auto error = dup_or_error.release_error();
if (error.code() != EBADF) {
warnln("nohup: error redirecting stderr to stdout: {}", strerror(error.code()));
return 127;
}
// NOTE: Standard output must be closed, so "...the same output shall
// instead be appended to the end of the nohup.out file..."
dup_out_file(STDERR_FILENO);
}
}
TRY(Core::System::signal(SIGHUP, SIG_IGN));
TRY(args.try_prepend(utility));
auto exec_or_error = Core::System::exec(utility, args.span(), Core::System::SearchInPath::Yes);
if (exec_or_error.is_error()) {
auto error = exec_or_error.release_error();
warnln("nohup: error while calling exec: {}", strerror(error.code()));
return error.code() == ENOENT ? 127 : 126;
}
return 0;
}