ladybird/Userland/Utilities/nohup.cpp
Kemal Zebari 02d8aaa2e8 nohup: Use return code 127 for errors caught by serenity_main()
For any errors that occur during the runtime of nohup, POSIX uses
a 127 return code.
2024-01-19 12:16:56 -07:00

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;
ByteString 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)
{
Main::set_return_code_for_errors(127);
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;
}