harakit/src/intcmp.c

92 lines
2.5 KiB
C

/*
* Copyright (c) 2023 DTB <trinity@trinity.moe>
* Copyright (c) 2024 Emma Tebibyte <emma@tebibyte.media>
* SPDX-License-Identifier: AGPL-3.0-or-later
*
* This program is free software: you can redistribute it and/or modify it under
* the terms of the GNU Affero General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
* details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see https://www.gnu.org/licenses/.
*/
#include <errno.h> /* errno */
#include <stdio.h> /* fprintf(3), stderr */
#include <stdlib.h> /* strtol(3), size_t, EXIT_FAILURE */
#include <unistd.h> /* getopt(3), optind */
#include <sysexits.h> /* EX_OK, EX_USAGE */
#define /* 0b00? */ EQUAL 0x01 /* | -e | 0b001 | 1 */
#define /* 0b0?0 */ GREATER 0x02 /* | -g | 0b010 | 2 */
/* Equal | Greater 0x03 | -ge | 0b011 | 3 */
#define /* 0b?00 */ LESSER 0x04 /* | -l | 0b100 | 4 */
/* Equal | Lesser 0x05 | -le | 0b101 | 5 */
/* (Inequal) Greater | Lesser 0x06 | -gl | 0b110 | 6 */
char *program_name = "intcmp";
static int
usage(char *argv0) {
(void)fprintf(stderr, "Usage: %s [-egl] integer integer...\n", argv0);
return EX_USAGE;
}
int main(int argc, char *argv[]) {
int c;
size_t i;
unsigned char mode;
int r; /* reference integer */
mode = 0;
if (argc < 3) {
return usage(argv[0] == NULL ? program_name : argv[0]);
}
while ((c = getopt(argc, argv, "egl")) != -1) {
switch (c) {
case 'e': mode |= EQUAL; break;
case 'g': mode |= GREATER; break;
case 'l': mode |= LESSER; break;
default: return usage(argv[0]);
}
}
if (optind + 2 /* ref cmp */ > argc) { return usage(argv[0]); }
i = optind;
do {
r = c;
c = strtol(argv[i], &argv[i], 10);
if (*argv[i] != '\0' || errno != 0) {
fprintf(
stderr,
"%s: argument #%d: Invalid integer\n",
argv[0],
(int)i
);
return EX_USAGE;
}
if (i == optind) { continue; }
/* rule enforcement; if a mode isn't permitted and the numbers
* correspond to it, return 1 */
if ( (!(mode & EQUAL) && r == c)
|| (!(mode & GREATER) && r > c)
|| (!(mode & LESSER) && r < c)
) { return 1; }
} while (++i < argc);
return EX_OK;
}