/* $OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $ */ /* * Copyright (c) 1998, 2015 Todd C. Miller * * 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 #include /* * Appends src to string dst of size dsize (unlike strncat, dsize is the * full size of dst, not space left). At most dsize-1 characters * will be copied. Always NUL terminates (unless dsize <= strlen(dst)). * Returns strlen(src) + MIN(dsize, strlen(initial dst)). * If retval >= dsize, truncation occurred. */ size_t strlcat(char *dst, const char *src, size_t dsize) { const char *odst = dst; const char *osrc = src; size_t n = dsize; size_t dlen; /* Find the end of dst and adjust bytes left but don't go past end. */ while (n-- != 0 && *dst != '\0') dst++; dlen = dst - odst; n = dsize - dlen; if (n-- == 0) return(dlen + strlen(src)); while (*src != '\0') { if (n != 0) { *dst++ = *src; n--; } src++; } *dst = '\0'; return(dlen + (src - osrc)); /* count does not include NUL */ } DEF_WEAK(strlcat);