/*      $OpenBSD: test___freadptr.c,v 1.1 2025/05/25 00:20:54 yasuoka Exp $     */

/*
 * Copyright (c) 2025 YASUOKA Masahiko <yasuoka@yasuoka.net>
 *
 * Permission to use, copy, modify, and 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.
 */

#include <sys/types.h>
#include <assert.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>

/* we use assert() */
#undef  NDEBUG

#define TMPFILENAME     "test___freadptr.tmp"

void test___freadptr0(void);

/* test __freadptr() and __freadptrinc() */
void
test___freadptr0(void)
{
        FILE            *fp;
        int              r;
        ssize_t          s;
        const char      *p;

        fp = fopen(TMPFILENAME, "w");
        assert(fp != NULL);
        r = fputs("Hello world", fp);
        assert(r >= 0);
        r = fclose(fp);

        fp = fopen(TMPFILENAME, "r");
        assert(fgetc(fp) == 'H');
        p = __freadptr(fp, &s);
        assert(p != NULL);
        assert(s > 4);          /* this test assume this (not by the spec) */
        assert(*p == 'e');
        assert(strncmp(p, "ello world", s) == 0);

        __freadptrinc(fp, 4);
        assert(fgetc(fp) == ' ');

        ungetc('A', fp);
        ungetc('A', fp);
        ungetc('A', fp);
        p = __freadptr(fp, &s);
        assert(s > 0);
        assert(*p == 'A');
        /* ptr will contains only the pushback buffer */
        assert(strncmp(p, "AAAworld", s) == 0);

        r = fclose(fp);
        assert(r == 0);
}

int
main(int argc, char *argv[])
{
        test___freadptr0();

        exit(0);
}