Standard Libraries for EDK II.

[mirror_edk2.git] / StdLib / LibC / Stdio / fgetstr.c

/*  $NetBSD: fgetstr.c,v 1.4 2006/11/24 19:46:58 christos Exp $ */\r
\r
/*-\r
 * Copyright (c) 1990, 1993\r
 *  The Regents of the University of California.  All rights reserved.\r
 *\r
 * This code is derived from software contributed to Berkeley by\r
 * Chris Torek.\r
 *\r
 * Redistribution and use in source and binary forms, with or without\r
 * modification, are permitted provided that the following conditions\r
 * are met:\r
 * 1. Redistributions of source code must retain the above copyright\r
 *    notice, this list of conditions and the following disclaimer.\r
 * 2. Redistributions in binary form must reproduce the above copyright\r
 *    notice, this list of conditions and the following disclaimer in the\r
 *    documentation and/or other materials provided with the distribution.\r
 * 3. Neither the name of the University nor the names of its contributors\r
 *    may be used to endorse or promote products derived from this software\r
 *    without specific prior written permission.\r
 *\r
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND\r
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE\r
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\r
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE\r
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\r
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS\r
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)\r
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT\r
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY\r
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF\r
 * SUCH DAMAGE.\r
 */\r
#include  <LibConfig.h>\r
#include <sys/EfiCdefs.h>\r
#if defined(LIBC_SCCS) && !defined(lint)\r
#if 0\r
static char sccsid[] = "@(#)fgetline.c  8.1 (Berkeley) 6/4/93";\r
#else\r
__RCSID("$NetBSD: fgetstr.c,v 1.4 2006/11/24 19:46:58 christos Exp $");\r
#endif\r
#endif /* LIBC_SCCS and not lint */\r
\r
#include "namespace.h"\r
\r
#include <assert.h>\r
#include <stdio.h>\r
#include <stdlib.h>\r
#include <string.h>\r
#include "reentrant.h"\r
#include "local.h"\r
\r
/*\r
 * Expand the line buffer.  Return -1 on error.\r
#ifdef notdef\r
 * The `new size' does not account for a terminating '\0',\r
 * so we add 1 here.\r
#endif\r
 */\r
int\r
__slbexpand(FILE *fp, size_t newsize)\r
{\r
  void *p;\r
\r
#ifdef notdef\r
  ++newsize;\r
#endif\r
  _DIAGASSERT(fp != NULL);\r
\r
  if ((size_t)fp->_lb._size >= newsize)\r
    return (0);\r
  if ((p = realloc(fp->_lb._base, newsize)) == NULL)\r
    return (-1);\r
  fp->_lb._base = p;\r
  fp->_lb._size = (int)newsize;\r
  return (0);\r
}\r
\r
/*\r
 * Get an input line.  The returned pointer often (but not always)\r
 * points into a stdio buffer.  Fgetline does not alter the text of\r
 * the returned line (which is thus not a C string because it will\r
 * not necessarily end with '\0'), but does allow callers to modify\r
 * it if they wish.  Thus, we set __SMOD in case the caller does.\r
 */\r
char *\r
__fgetstr(FILE *fp, size_t *lenp, int sep)\r
{\r
  unsigned char *p;\r
  size_t len;\r
  size_t off;\r
\r
  _DIAGASSERT(fp != NULL);\r
  _DIAGASSERT(lenp != NULL);\r
\r
  /* make sure there is input */\r
  if (fp->_r <= 0 && __srefill(fp)) {\r
    *lenp = 0;\r
    return (NULL);\r
  }\r
\r
  /* look for a newline in the input */\r
  if ((p = memchr((void *)fp->_p, sep, (size_t)fp->_r)) != NULL) {\r
    char *ret;\r
\r
    /*\r
     * Found one.  Flag buffer as modified to keep fseek from\r
     * `optimising' a backward seek, in case the user stomps on\r
     * the text.\r
     */\r
    p++;    /* advance over it */\r
    ret = (char *)fp->_p;\r
    *lenp = len = p - fp->_p;\r
    fp->_flags |= __SMOD;\r
    fp->_r -= (int)len;\r
    fp->_p = p;\r
    return (ret);\r
  }\r
\r
  /*\r
   * We have to copy the current buffered data to the line buffer.\r
   * As a bonus, though, we can leave off the __SMOD.\r
   *\r
   * OPTIMISTIC is length that we (optimistically) expect will\r
   * accommodate the `rest' of the string, on each trip through the\r
   * loop below.\r
   */\r
#define OPTIMISTIC 80\r
\r
  for (len = fp->_r, off = 0;; len += fp->_r) {\r
    size_t diff;\r
\r
    /*\r
     * Make sure there is room for more bytes.  Copy data from\r
     * file buffer to line buffer, refill file and look for\r
     * newline.  The loop stops only when we find a newline.\r
     */\r
    if (__slbexpand(fp, len + OPTIMISTIC))\r
      goto error;\r
    (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,\r
        len - off);\r
    off = len;\r
    if (__srefill(fp))\r
      break;  /* EOF or error: return partial line */\r
    if ((p = memchr((void *)fp->_p, sep, (size_t)fp->_r)) == NULL)\r
      continue;\r
\r
    /* got it: finish up the line (like code above) */\r
    p++;\r
    diff = p - fp->_p;\r
    len += diff;\r
    if (__slbexpand(fp, len))\r
      goto error;\r
    (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,\r
        diff);\r
    fp->_r -= (int)diff;\r
    fp->_p = p;\r
    break;\r
  }\r
  *lenp = len;\r
#ifdef notdef\r
  fp->_lb._base[len] = 0;\r
#endif\r
  return ((char *)fp->_lb._base);\r
\r
error:\r
  *lenp = 0;    /* ??? */\r
  return (NULL);    /* ??? */\r
}\r