/* * 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_tstrlcat(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 */}/* * 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_tstrlcpy(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 */} |
