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/*
* Copyright (c) 2020, Nico Weber <thakis@chromium.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/DeprecatedString.h>
#include <AK/Format.h>
#include <AK/StdLibExtras.h>
#include <AK/Vector.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char const* const g_usage = R"(Usage:
seq [-h|--help]
seq LAST
seq FIRST LAST
seq FIRST INCREMENT LAST
)";
static void print_usage(FILE* stream)
{
fputs(g_usage, stream);
}
static double get_double(char const* name, StringView d_string, size_t* number_of_decimals)
{
auto d = d_string.to_double();
if (!d.has_value()) {
warnln("{}: invalid argument \"{}\"", name, d_string);
print_usage(stderr);
exit(1);
}
if (auto dot = d_string.find('.'); dot.has_value())
*number_of_decimals = d_string.length() - *dot - 1;
else
*number_of_decimals = 0;
return *d;
}
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
TRY(Core::System::pledge("stdio"));
TRY(Core::System::unveil(nullptr, nullptr));
StringView separator = "\n"sv;
StringView terminator = ""sv;
Vector<StringView> parameters;
Core::ArgsParser args_parser;
args_parser.add_option(separator, "Characters to print after each number (default: \\n)", "separator", 's', "separator");
args_parser.add_option(terminator, "Characters to print at the end of the sequence", "terminator", 't', "terminator");
args_parser.add_positional_argument(parameters, "1 to 3 parameters, interpreted as LAST, FIRST LAST, or FIRST INCREMENT LAST", "parameters");
args_parser.parse(arguments);
double start = 1;
double step = 1;
double end = 1;
size_t number_of_start_decimals = 0;
size_t number_of_step_decimals = 0;
size_t number_of_end_decimals = 0;
switch (parameters.size()) {
case 1:
end = get_double(arguments.argv[0], parameters[0], &number_of_end_decimals);
break;
case 2:
start = get_double(arguments.argv[0], parameters[0], &number_of_start_decimals);
end = get_double(arguments.argv[0], parameters[1], &number_of_end_decimals);
break;
case 3:
start = get_double(arguments.argv[0], parameters[0], &number_of_start_decimals);
step = get_double(arguments.argv[0], parameters[1], &number_of_step_decimals);
end = get_double(arguments.argv[0], parameters[2], &number_of_end_decimals);
break;
default:
warnln("{}: unexpected number of arguments", arguments.argv[0]);
print_usage(stderr);
return 1;
}
if (step == 0) {
warnln("{}: increment must not be 0", arguments.argv[0]);
return 1;
}
if (__builtin_isnan(start) || __builtin_isnan(step) || __builtin_isnan(end)) {
warnln("{}: start, step, and end must not be NaN", arguments.argv[0]);
return 1;
}
size_t number_of_decimals = max(number_of_start_decimals, max(number_of_step_decimals, number_of_end_decimals));
int n = static_cast<int>((end - start) / step);
double d = start;
for (int i = 0; i <= n; ++i) {
char buf[40];
snprintf(buf, sizeof(buf), "%f", d);
if (char* dot = strchr(buf, '.')) {
if (number_of_decimals == 0)
*dot = '\0';
else if ((dot - buf) + 1 + number_of_decimals < (int)sizeof(buf))
dot[1 + number_of_decimals] = '\0';
}
out("{}{}", buf, separator);
d += step;
}
if (!terminator.is_empty())
out(terminator);
return 0;
}
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