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/*
* Copyright (c) 2023 Mitchell Riedstra
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*
* A fairly basic interface to `strftime`, since dates are apparently difficult
* to handle with regular command line utilites and the POSIX spec for `date`
* is rather lacking.
*/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <errno.h>
void
help()
{
puts("strftime <fmt> [timestamp]");
exit(1);
}
int
main(int argc, char **argv) {
time_t t = time(NULL);
char **a = argv+1;
struct tm *tm;
char *fmt;
char out[256] = {0};
if (!*a) {
help();
}
fmt = *a;
a++;
if (*a) {
errno = 0;
t = strtol(*a, NULL, 10);
if (errno != 0) {
perror("strtol");
exit(1);
}
}
tm = localtime(&t);
if (strftime(out, 256, fmt, tm) == 0) {
perror("strftime");
exit(1);
}
puts(out);
}
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