1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/*
* Copyright (c) 2022, Eli Youngs <eli.m.youngs@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/CharacterTypes.h>
#include <AK/GenericLexer.h>
#include <AK/Vector.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/File.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <LibRegex/RegexMatcher.h>
#include <LibRegex/RegexOptions.h>
struct SubstitutionCommand {
Regex<PosixExtended> regex;
StringView replacement;
PosixOptions options;
Optional<StringView> output_filepath;
};
static Vector<StringView> split_flags(StringView const& input)
{
Vector<StringView> flags;
auto lexer = GenericLexer(input);
while (!lexer.is_eof()) {
StringView flag;
if (lexer.next_is(is_ascii_digit)) {
flag = lexer.consume_while(is_ascii_digit);
} else if (lexer.peek() == 'w') {
flag = lexer.consume_all();
} else {
flag = lexer.consume(1);
}
flags.append(flag);
}
return flags;
}
static ErrorOr<SubstitutionCommand> parse_command(StringView command)
{
auto generic_error_message = "Incomplete substitution command"sv;
auto lexer = GenericLexer(command);
auto address = lexer.consume_until('s');
if (!address.is_empty())
warnln("sed: Addresses are currently ignored");
if (!lexer.consume_specific('s'))
return Error::from_string_view(generic_error_message);
if (lexer.is_eof())
return Error::from_string_view(generic_error_message);
auto delimiter = lexer.consume();
if (delimiter == '\n' || delimiter == '\\')
return Error::from_string_literal("\\n and \\ cannot be used as delimiters.");
auto pattern = lexer.consume_until(delimiter);
if (pattern.is_empty())
return Error::from_string_literal("Substitution patterns cannot be empty.");
if (!lexer.consume_specific(delimiter))
return Error::from_string_view(generic_error_message);
auto replacement = lexer.consume_until(delimiter);
// According to Posix, "s/x/y" is an invalid substitution command.
// It must have a closing delimiter: "s/x/y/"
if (!lexer.consume_specific(delimiter))
return Error::from_string_literal("The substitution command was not properly terminated.");
PosixOptions options = PosixOptions(PosixFlags::Global | PosixFlags::SingleMatch);
Optional<StringView> output_filepath;
auto flags = split_flags(lexer.consume_all());
for (auto const& flag : flags) {
if (flag.starts_with('w')) {
auto flag_filepath = flag.substring_view(1).trim_whitespace();
if (flag_filepath.is_empty())
return Error::from_string_literal("No filepath was provided for the 'w' flag.");
output_filepath = flag_filepath;
} else if (flag == "g"sv) {
// Allow multiple matches per line by un-setting the SingleMatch flag
options &= ~PosixFlags::SingleMatch;
} else if (flag == "i"sv || flag == "I"sv) {
options |= PosixFlags::Insensitive;
} else {
warnln("sed: Unsupported flag: {}", flag);
}
}
return SubstitutionCommand { Regex<PosixExtended> { pattern }, replacement, options, output_filepath };
}
ErrorOr<int> serenity_main(Main::Arguments args)
{
TRY(Core::System::pledge("stdio cpath rpath wpath"));
Core::ArgsParser args_parser;
StringView command_input;
Vector<StringView> filepaths;
args_parser.add_positional_argument(command_input, "Command", "command_input", Core::ArgsParser::Required::Yes);
args_parser.add_positional_argument(filepaths, "File", "file", Core::ArgsParser::Required::No);
args_parser.parse(args);
auto command = TRY(parse_command(command_input));
Optional<NonnullOwnPtr<Core::File>> maybe_output_file;
if (command.output_filepath.has_value())
maybe_output_file = TRY(Core::File::open_file_or_standard_stream(command.output_filepath.release_value(), Core::File::OpenMode::Write));
if (filepaths.is_empty())
filepaths = { "-"sv };
Array<u8, PAGE_SIZE> buffer {};
for (auto const& filepath : filepaths) {
auto file_unbuffered = TRY(Core::File::open_file_or_standard_stream(filepath, Core::File::OpenMode::Read));
auto file = TRY(Core::BufferedFile::create(move(file_unbuffered)));
while (!file->is_eof()) {
auto line = TRY(file->read_line(buffer));
// Substitutions can apply to blank lines in the middle of a file,
// but not to the trailing newline that marks the end of a file.
if (line.is_empty() && file->is_eof())
break;
auto result = command.regex.replace(line, command.replacement, command.options);
outln(result);
if (maybe_output_file.has_value()) {
auto const& output_file = maybe_output_file.value();
TRY(output_file->write_until_depleted(result.bytes()));
TRY(output_file->write_until_depleted("\n"sv.bytes()));
}
}
}
return 0;
}
|
