ladybird/Userland/Utilities/man.cpp

112 lines
4.1 KiB
C++

/*
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Assertions.h>
#include <AK/ByteBuffer.h>
#include <AK/DeprecatedString.h>
#include <AK/Utf8View.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/File.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <LibManual/Node.h>
#include <LibManual/PageNode.h>
#include <LibManual/SectionNode.h>
#include <LibMarkdown/Document.h>
#include <spawn.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <unistd.h>
static ErrorOr<pid_t> pipe_to_pager(DeprecatedString const& command)
{
char const* argv[] = { "sh", "-c", command.characters(), nullptr };
auto stdout_pipe = TRY(Core::System::pipe2(O_CLOEXEC));
posix_spawn_file_actions_t action;
posix_spawn_file_actions_init(&action);
posix_spawn_file_actions_adddup2(&action, stdout_pipe[0], STDIN_FILENO);
pid_t pid = TRY(Core::System::posix_spawnp("sh"sv, &action, nullptr, const_cast<char**>(argv), environ));
posix_spawn_file_actions_destroy(&action);
TRY(Core::System::dup2(stdout_pipe[1], STDOUT_FILENO));
TRY(Core::System::close(stdout_pipe[1]));
TRY(Core::System::close(stdout_pipe[0]));
return pid;
}
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
int view_width = 0;
if (isatty(STDOUT_FILENO) != 0) {
struct winsize ws;
if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0)
view_width = ws.ws_col;
}
if (view_width == 0)
view_width = 80;
TRY(Core::System::pledge("stdio rpath exec proc"));
TRY(Core::System::unveil("/usr/share/man", "r"));
TRY(Core::System::unveil("/bin", "x"));
TRY(Core::System::unveil(nullptr, nullptr));
DeprecatedString section_argument;
DeprecatedString name_argument;
DeprecatedString pager;
Core::ArgsParser args_parser;
args_parser.set_general_help("Read manual pages. Try 'man man' to get started.");
args_parser.add_positional_argument(section_argument, "Section of the man page", "section");
args_parser.add_positional_argument(name_argument, "Name of the man page", "name", Core::ArgsParser::Required::No);
args_parser.add_option(pager, "Pager to pipe the man page to", "pager", 'P', "pager");
args_parser.parse(arguments);
Vector<StringView, 2> query_parameters;
if (!section_argument.is_empty())
query_parameters.append(section_argument);
if (!name_argument.is_empty())
query_parameters.append(name_argument);
auto page = TRY(Manual::Node::try_create_from_query(query_parameters));
auto page_name = TRY(page->name());
auto const* section = static_cast<Manual::SectionNode const*>(page->parent());
if (pager.is_empty())
pager = TRY(String::formatted("less -P 'Manual Page {}({}) line %l?e (END):.'",
TRY(page_name.replace("'"sv, "'\\''"sv, ReplaceMode::FirstOnly)),
TRY(section->section_name().replace("'"sv, "'\\''"sv, ReplaceMode::FirstOnly))))
.to_deprecated_string();
pid_t pager_pid = TRY(pipe_to_pager(pager));
auto file = TRY(Core::File::open(TRY(page->path()), Core::File::OpenMode::Read));
TRY(Core::System::pledge("stdio proc"));
dbgln("Loading man page from {}", TRY(page->path()));
auto buffer = TRY(file->read_until_eof());
auto source = DeprecatedString::copy(buffer);
auto const title = TRY("SerenityOS manual"_string);
int spaces = max(view_width / 2 - page_name.code_points().length() - section->section_name().code_points().length() - title.code_points().length() / 2 - 4, 0);
outln("{}({}){}{}", page_name, section->section_name(), DeprecatedString::repeated(' ', spaces), title);
auto document = Markdown::Document::parse(source);
VERIFY(document);
DeprecatedString rendered = document->render_for_terminal(view_width);
outln("{}", rendered);
// FIXME: Remove this wait, it shouldn't be necessary but Shell does not
// resume properly without it. This wait also breaks <C-z> backgrounding
fclose(stdout);
int wstatus;
waitpid(pager_pid, &wstatus, 0);
return 0;
}