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- /*
- * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
- #include <AK/ScopeGuard.h>
- #include <AK/StringView.h>
- #include <string.h>
- #include <unistd.h>
- // https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsubopt.html
- int getsubopt(char** option_array, char* const* tokens, char** option_value)
- {
- if (**option_array == '\0')
- return -1;
- auto const* option_ptr = *option_array;
- StringView option_string { option_ptr, strlen(option_ptr) };
- auto possible_comma_location = option_string.find(',');
- char* option_end = const_cast<char*>(option_string.characters_without_null_termination()) + possible_comma_location.value_or(option_string.length());
- auto possible_equals_char_location = option_string.find('=');
- char* value_start = option_end;
- if (possible_equals_char_location.has_value()) {
- value_start = const_cast<char*>(option_string.characters_without_null_termination()) + possible_equals_char_location.value();
- }
- ScopeGuard ensure_end_array_contains_null_char([&]() {
- if (*option_end != '\0')
- *option_end++ = '\0';
- *option_array = option_end;
- });
- for (int count = 0; tokens[count] != NULL; ++count) {
- auto const* token = tokens[count];
- StringView token_stringview { token, strlen(token) };
- if (!option_string.starts_with(token_stringview))
- continue;
- if (tokens[count][value_start - *option_array] != '\0')
- continue;
- *option_value = value_start != option_end ? value_start + 1 : nullptr;
- return count;
- }
- // Note: The current sub-option does not match any option, so prepare to tell this
- // to the application.
- *option_value = *option_array;
- return -1;
- }
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