ladybird/Userland/Utilities/cut.cpp
Tim Ledbetter dedbc17160 cut: Add -s option to suppress lines without field delimiters
If this option is not specified, lines that contain to field
delimiters will be printed unmodified.
2023-06-26 19:49:34 +02:00

265 lines
8.4 KiB
C++

/*
* Copyright (c) 2019-2020, Marios Prokopakis <mariosprokopakis@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/DeprecatedString.h>
#include <AK/QuickSort.h>
#include <AK/StdLibExtras.h>
#include <AK/Vector.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/File.h>
#include <LibMain/Main.h>
#include <stdio.h>
#include <stdlib.h>
struct Range {
size_t m_from { 1 };
size_t m_to { SIZE_MAX };
[[nodiscard]] bool intersects(Range const& other) const
{
return !(other.m_from > m_to || other.m_to < m_from);
}
void merge(Range const& other)
{
// Can't merge two ranges that are disjoint.
VERIFY(intersects(other));
m_from = min(m_from, other.m_from);
m_to = max(m_to, other.m_to);
}
};
static bool expand_list(DeprecatedString& list, Vector<Range>& ranges)
{
Vector<DeprecatedString> tokens = list.split(',', SplitBehavior::KeepEmpty);
for (auto& token : tokens) {
if (token.length() == 0) {
warnln("cut: byte/character positions are numbered from 1");
return false;
}
if (token == "-") {
warnln("cut: invalid range with no endpoint: {}", token);
return false;
}
if (token[0] == '-') {
auto index = token.substring(1, token.length() - 1).to_uint();
if (!index.has_value()) {
warnln("cut: invalid byte/character position '{}'", token);
return false;
}
if (index.value() == 0) {
warnln("cut: byte/character positions are numbered from 1");
return false;
}
ranges.append({ 1, index.value() });
} else if (token[token.length() - 1] == '-') {
auto index = token.substring(0, token.length() - 1).to_uint();
if (!index.has_value()) {
warnln("cut: invalid byte/character position '{}'", token);
return false;
}
if (index.value() == 0) {
warnln("cut: byte/character positions are numbered from 1");
return false;
}
ranges.append({ index.value(), SIZE_MAX });
} else {
auto range = token.split('-', SplitBehavior::KeepEmpty);
if (range.size() == 2) {
auto index1 = range[0].to_uint();
if (!index1.has_value()) {
warnln("cut: invalid byte/character position '{}'", range[0]);
return false;
}
auto index2 = range[1].to_uint();
if (!index2.has_value()) {
warnln("cut: invalid byte/character position '{}'", range[1]);
return false;
}
if (index1.value() > index2.value()) {
warnln("cut: invalid decreasing range");
return false;
} else if (index1.value() == 0 || index2.value() == 0) {
warnln("cut: byte/character positions are numbered from 1");
return false;
}
ranges.append({ index1.value(), index2.value() });
} else if (range.size() == 1) {
auto index = range[0].to_uint();
if (!index.has_value()) {
warnln("cut: invalid byte/character position '{}'", range[0]);
return false;
}
if (index.value() == 0) {
warnln("cut: byte/character positions are numbered from 1");
return false;
}
ranges.append({ index.value(), index.value() });
} else {
warnln("cut: invalid byte or character range");
return false;
}
}
}
return true;
}
static void process_line_bytes(StringView line, Vector<Range> const& ranges)
{
for (auto& i : ranges) {
if (i.m_from >= line.length())
continue;
auto to = min(i.m_to, line.length());
auto sub_string = DeprecatedString(line).substring(i.m_from - 1, to - i.m_from + 1);
out("{}", sub_string);
}
outln();
}
static void process_line_fields(StringView line, Vector<Range> const& ranges, char delimiter, bool only_print_delimited_lines)
{
auto string_split = DeprecatedString(line).split(delimiter, SplitBehavior::KeepEmpty);
if (string_split.size() == 1) {
if (!only_print_delimited_lines)
outln("{}", line);
return;
}
Vector<DeprecatedString> output_fields;
for (auto& range : ranges) {
for (size_t i = range.m_from - 1; i < min(range.m_to, string_split.size()); i++) {
output_fields.append(string_split[i]);
}
}
outln("{}", DeprecatedString::join(delimiter, output_fields));
}
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
DeprecatedString byte_list = "";
DeprecatedString fields_list = "";
DeprecatedString delimiter = "\t";
bool only_print_delimited_lines = false;
Vector<StringView> files;
Core::ArgsParser args_parser;
args_parser.add_positional_argument(files, "file(s) to cut", "file", Core::ArgsParser::Required::No);
args_parser.add_option(byte_list, "select only these bytes", "bytes", 'b', "list");
args_parser.add_option(fields_list, "select only these fields", "fields", 'f', "list");
args_parser.add_option(delimiter, "set a custom delimiter", "delimiter", 'd', "delimiter");
args_parser.add_option(only_print_delimited_lines, "suppress lines which don't contain any field delimiter characters", "only-delimited", 's');
args_parser.parse(arguments);
bool selected_bytes = (byte_list != "");
bool selected_fields = (fields_list != "");
int selected_options_count = (selected_bytes ? 1 : 0) + (selected_fields ? 1 : 0);
if (selected_options_count == 0) {
warnln("cut: you must specify a list of bytes, or fields");
args_parser.print_usage(stderr, arguments.strings[0]);
return 1;
}
if (selected_options_count > 1) {
warnln("cut: you must specify only one of bytes, or fields");
args_parser.print_usage(stderr, arguments.strings[0]);
return 1;
}
if (delimiter.length() != 1) {
warnln("cut: the delimiter must be a single character");
args_parser.print_usage(stderr, arguments.strings[0]);
return 1;
}
DeprecatedString ranges_list;
Vector<Range> ranges_vector;
if (selected_bytes) {
ranges_list = byte_list;
} else if (selected_fields) {
ranges_list = fields_list;
} else {
// This should never happen, since we already checked the options count above.
VERIFY_NOT_REACHED();
}
auto expansion_successful = expand_list(ranges_list, ranges_vector);
if (!expansion_successful) {
args_parser.print_usage(stderr, arguments.strings[0]);
return 1;
}
quick_sort(ranges_vector, [](auto& a, auto& b) { return a.m_from < b.m_from; });
Vector<Range> disjoint_ranges;
for (auto& range : ranges_vector) {
if (disjoint_ranges.is_empty()) {
disjoint_ranges.append(range);
continue;
}
Range& last_range = disjoint_ranges.last();
if (!last_range.intersects(range)) {
disjoint_ranges.append(range);
continue;
}
last_range.merge(range);
}
if (files.is_empty())
files.append(""sv);
/* Process each file */
for (auto const filename : files) {
auto maybe_file = Core::File::open_file_or_standard_stream(filename, Core::File::OpenMode::Read);
if (maybe_file.is_error()) {
warnln("cut: Could not open file '{}'", filename.is_empty() ? "stdin"sv : filename);
continue;
}
auto file = TRY(Core::InputBufferedFile::create(maybe_file.release_value()));
Array<u8, PAGE_SIZE> buffer;
while (TRY(file->can_read_line())) {
auto line = TRY(file->read_line(buffer));
if (line == "\n" && TRY(file->can_read_line()))
break;
if (selected_bytes) {
process_line_bytes(line, disjoint_ranges);
} else if (selected_fields) {
process_line_fields(line, disjoint_ranges, delimiter[0], only_print_delimited_lines);
} else {
VERIFY_NOT_REACHED();
}
}
}
return 0;
}