strxnmov.cc

/* Copyright (c) 2000, 2024, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is designed to work with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have either included with
   the program or referenced in the documentation.

   Without limiting anything contained in the foregoing, this file,
   which is part of C Driver for MySQL (Connector/C), is also subject to the
   Universal FOSS Exception, version 1.0, a copy of which can be found at
   http://oss.oracle.com/licenses/universal-foss-exception.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/*  File   : strxnmov.c
    Author : Richard A. O'Keefe.
    Updated: 2 June 1984
    Defines: strxnmov()

    strxnmov(dst, len, src1, ..., srcn, NullS)
    moves the first len characters of the concatenation of src1,...,srcn
    to dst and add a closing NUL character.
    It is just like strnmov except that it concatenates multiple sources.
    Beware: the last argument should be the null character pointer.
    Take VERY great care not to omit it!  Also be careful to use NullS
    and NOT to use 0, as on some machines 0 is not the same size as a
    character pointer, or not the same bit pattern as NullS.

    NOTE
      strxnmov is like strnmov in that it moves up to len
      characters; dst will be padded on the right with one '\0' character.
      if total-string-length >= length then dst[length] will be set to \0
*/

#include <stdarg.h>
#include <stddef.h>

#include "m_string.h"  // IWYU pragma: keep

char *strxnmov(char *dst, size_t len, const char *src, ...) {
  va_list pvar;
  char *end_of_dst = dst + len;

  va_start(pvar, src);
  while (src != NullS) {
    do {
      if (dst == end_of_dst) goto end;
    } while ((*dst++ = *src++));
    dst--;
    src = va_arg(pvar, char *);
  }
end:
  *dst = 0;
  va_end(pvar);
  return dst;
}