/* -*- mode: c; c-file-style: "bsd"; indent-tabs-mode: t -*- */
/*
 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * 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.
 */

/* Provide strlcpy and strlcat for platforms that don't have them. */

#include "k5-platform.h"
#include <sys/types.h>
#include <string.h>

/*
 * Copy src to string dst of size siz.  At most siz-1 characters
 * will be copied.  Always NUL terminates (unless siz == 0).
 * Returns strlen(src); if retval >= siz, truncation occurred.
 */
size_t
krb5int_strlcpy(char *dst, const char *src, size_t siz)
{
        char *d = dst;
        const char *s = src;
        size_t n = siz;

        /* Copy as many bytes as will fit */
        if (n != 0) {
                while (--n != 0) {
                        if ((*d++ = *s++) == '\0')
                                break;
                }
        }

        /* Not enough room in dst, add NUL and traverse rest of src */
        if (n == 0) {
                if (siz != 0)
                        *d = '\0';              /* NUL-terminate dst */
                while (*s++)
                        ;
        }

        return(s - src - 1);    /* count does not include NUL */
}

/*
 * Appends src to string dst of size siz (unlike strncat, siz is the
 * full size of dst, not space left).  At most siz-1 characters
 * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
 * Returns strlen(src) + MIN(siz, strlen(initial dst)).
 * If retval >= siz, truncation occurred.
 */
size_t
krb5int_strlcat(char *dst, const char *src, size_t siz)
{
        char *d = dst;
        const char *s = src;
        size_t n = siz;
        size_t dlen;

        /* Find the end of dst and adjust bytes left but don't go past end */
        while (n-- != 0 && *d != '\0')
                d++;
        dlen = d - dst;
        n = siz - dlen;

        if (n == 0)
                return(dlen + strlen(s));
        while (*s != '\0') {
                if (n != 1) {
                        *d++ = *s;
                        n--;
                }
                s++;
        }
        *d = '\0';

        return(dlen + (s - src));       /* count does not include NUL */
}