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/*
* Copyright (c) 2020, Nico Weber <thakis@chromium.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <AK/StdLibExtras.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);
return;
}
static double get_double(char const* name, char const* d_string, int* number_of_decimals)
{
char* end;
double d = strtod(d_string, &end);
if (d == 0 && end == d_string) {
warnln("{}: invalid argument \"{}\"", name, d_string);
print_usage(stderr);
exit(1);
}
if (char const* dot = strchr(d_string, '.'))
*number_of_decimals = strlen(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));
for (size_t i = 1; i < arguments.strings.size(); i++) {
if (arguments.strings[i] == "--help"sv || arguments.strings[i] == "-h") {
out("HELP");
print_usage(stdout);
exit(0);
}
}
double start = 1, step = 1, end = 1;
int number_of_start_decimals = 0, number_of_step_decimals = 0, number_of_end_decimals = 0;
switch (arguments.strings.size()) {
case 2:
end = get_double(arguments.argv[0], arguments.argv[1], &number_of_end_decimals);
break;
case 3:
start = get_double(arguments.argv[0], arguments.argv[1], &number_of_start_decimals);
end = get_double(arguments.argv[0], arguments.argv[2], &number_of_end_decimals);
break;
case 4:
start = get_double(arguments.argv[0], arguments.argv[1], &number_of_start_decimals);
step = get_double(arguments.argv[0], arguments.argv[2], &number_of_step_decimals);
end = get_double(arguments.argv[0], arguments.argv[3], &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;
}
int number_of_decimals = max(number_of_start_decimals, max(number_of_step_decimals, number_of_end_decimals));
int n = (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';
}
outln("{}", buf);
d += step;
}
return 0;
}
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