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/*
* Copyright (c) 2020, Nico Weber <thakis@chromium.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/StdLibExtras.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
const char* 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(const char* name, const char* d_string, int* number_of_decimals)
{
char* end;
double d = strtod(d_string, &end);
if (d == 0 && end == d_string) {
fprintf(stderr, "%s: invalid argument \"%s\"\n", name, d_string);
print_usage(stderr);
exit(1);
}
if (char* dot = strchr(d_string, '.'))
*number_of_decimals = strlen(dot + 1);
else
*number_of_decimals = 0;
return d;
}
int main(int argc, const char* argv[])
{
if (pledge("stdio", nullptr) < 0) {
perror("pledge");
return 1;
}
if (unveil(nullptr, nullptr) < 0) {
perror("unveil");
return 1;
}
for (int i = 1; i < argc; i++) {
if (strcmp(argv[i], "--help") == 0 || strcmp(argv[i], "-h") == 0) {
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 (argc) {
case 2:
end = get_double(argv[0], argv[1], &number_of_end_decimals);
break;
case 3:
start = get_double(argv[0], argv[1], &number_of_start_decimals);
end = get_double(argv[0], argv[2], &number_of_end_decimals);
break;
case 4:
start = get_double(argv[0], argv[1], &number_of_start_decimals);
step = get_double(argv[0], argv[2], &number_of_step_decimals);
end = get_double(argv[0], argv[3], &number_of_end_decimals);
break;
default:
fprintf(stderr, "%s: unexpected number of arguments\n", argv[0]);
print_usage(stderr);
return 1;
}
if (step == 0) {
fprintf(stderr, "%s: increment must not be 0\n", argv[0]);
return 1;
}
if (__builtin_isnan(start) || __builtin_isnan(step) || __builtin_isnan(end)) {
fprintf(stderr, "%s: start, step, and end must not be NaN\n", 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';
}
printf("%s\n", buf);
d += step;
}
return 0;
}
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