jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <AK/Assertions.h>
8#include <AK/ByteBuffer.h>
9#include <AK/DeprecatedString.h>
10#include <AK/Utf8View.h>
11#include <LibCore/ArgsParser.h>
12#include <LibCore/File.h>
13#include <LibCore/System.h>
14#include <LibMain/Main.h>
15#include <LibManual/Node.h>
16#include <LibManual/PageNode.h>
17#include <LibManual/SectionNode.h>
18#include <LibMarkdown/Document.h>
19#include <spawn.h>
20#include <sys/ioctl.h>
21#include <sys/wait.h>
22#include <unistd.h>
23
24static ErrorOr<pid_t> pipe_to_pager(DeprecatedString const& command)
25{
26 char const* argv[] = { "sh", "--skip-shellrc", "-c", command.characters(), nullptr };
27
28 auto stdout_pipe = TRY(Core::System::pipe2(O_CLOEXEC));
29
30 posix_spawn_file_actions_t action;
31 posix_spawn_file_actions_init(&action);
32 posix_spawn_file_actions_adddup2(&action, stdout_pipe[0], STDIN_FILENO);
33
34 pid_t pid = TRY(Core::System::posix_spawnp("sh"sv, &action, nullptr, const_cast<char**>(argv), environ));
35 posix_spawn_file_actions_destroy(&action);
36
37 TRY(Core::System::dup2(stdout_pipe[1], STDOUT_FILENO));
38 TRY(Core::System::close(stdout_pipe[1]));
39 TRY(Core::System::close(stdout_pipe[0]));
40 return pid;
41}
42
43ErrorOr<int> serenity_main(Main::Arguments arguments)
44{
45 int view_width = 0;
46 if (isatty(STDOUT_FILENO) != 0) {
47 struct winsize ws;
48 if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0)
49 view_width = ws.ws_col;
50 }
51
52 if (view_width == 0)
53 view_width = 80;
54
55 TRY(Core::System::pledge("stdio rpath exec proc"));
56 TRY(Core::System::unveil("/usr/share/man", "r"));
57 TRY(Core::System::unveil("/bin", "x"));
58 TRY(Core::System::unveil(nullptr, nullptr));
59
60 DeprecatedString section_argument;
61 DeprecatedString name_argument;
62 DeprecatedString pager;
63
64 Core::ArgsParser args_parser;
65 args_parser.set_general_help("Read manual pages. Try 'man man' to get started.");
66 args_parser.add_positional_argument(section_argument, "Section of the man page", "section");
67 args_parser.add_positional_argument(name_argument, "Name of the man page", "name", Core::ArgsParser::Required::No);
68 args_parser.add_option(pager, "Pager to pipe the man page to", "pager", 'P', "pager");
69 args_parser.parse(arguments);
70 Vector<StringView, 2> query_parameters;
71 if (!section_argument.is_empty())
72 query_parameters.append(section_argument);
73 if (!name_argument.is_empty())
74 query_parameters.append(name_argument);
75
76 auto page = TRY(Manual::Node::try_create_from_query(query_parameters));
77 auto page_name = TRY(page->name());
78 auto const* section = static_cast<Manual::SectionNode const*>(page->parent());
79
80 if (pager.is_empty())
81 pager = TRY(String::formatted("less -P 'Manual Page {}({}) line %l?e (END):.'",
82 TRY(page_name.replace("'"sv, "'\\''"sv, ReplaceMode::FirstOnly)),
83 TRY(section->section_name().replace("'"sv, "'\\''"sv, ReplaceMode::FirstOnly))))
84 .to_deprecated_string();
85 pid_t pager_pid = TRY(pipe_to_pager(pager));
86
87 auto file = TRY(Core::File::open(TRY(page->path()), Core::File::OpenMode::Read));
88
89 TRY(Core::System::pledge("stdio proc"));
90
91 dbgln("Loading man page from {}", TRY(page->path()));
92 auto buffer = TRY(file->read_until_eof());
93 auto source = DeprecatedString::copy(buffer);
94
95 auto const title = TRY("SerenityOS manual"_string);
96
97 int spaces = max(view_width / 2 - page_name.code_points().length() - section->section_name().code_points().length() - title.code_points().length() / 2 - 4, 0);
98 outln("{}({}){}{}", page_name, section->section_name(), DeprecatedString::repeated(' ', spaces), title);
99
100 auto document = Markdown::Document::parse(source);
101 VERIFY(document);
102
103 DeprecatedString rendered = document->render_for_terminal(view_width);
104 outln("{}", rendered);
105
106 // FIXME: Remove this wait, it shouldn't be necessary but Shell does not
107 // resume properly without it. This wait also breaks <C-z> backgrounding
108 fclose(stdout);
109 int wstatus;
110 waitpid(pager_pid, &wstatus, 0);
111 return 0;
112}