gonzui

    1: /*      $OpenBSD: fopen.c,v 1.7 2008/05/03 18:46:41 chl Exp $ */
    2: /*-
    3:  * Copyright (c) 1990, 1993
    4:  *      The Regents of the University of California.  All rights reserved.
    5:  *
    6:  * This code is derived from software contributed to Berkeley by
    7:  * Chris Torek.
    8:  *
    9:  * Redistribution and use in source and binary forms, with or without
   10:  * modification, are permitted provided that the following conditions
   11:  * are met:
   12:  * 1. Redistributions of source code must retain the above copyright
   13:  *    notice, this list of conditions and the following disclaimer.
   14:  * 2. Redistributions in binary form must reproduce the above copyright
   15:  *    notice, this list of conditions and the following disclaimer in the
   16:  *    documentation and/or other materials provided with the distribution.
   17:  * 3. Neither the name of the University nor the names of its contributors
   18:  *    may be used to endorse or promote products derived from this software
   19:  *    without specific prior written permission.
   20:  *
   21:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   22:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   23:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   24:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   25:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   26:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   27:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   28:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   29:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   30:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   31:  * SUCH DAMAGE.
   32:  */
   33: 
   34: #include <sys/types.h>
   35: #include <sys/stat.h>
   36: #include <fcntl.h>
   37: #include <limits.h>
   38: #include <stdio.h>
   39: #include <errno.h>
   40: #include <unistd.h>
   41: #include "local.h"
   42: 
   43: FILE *
   44: fopen_eno(const char *file, const char *mode, int *eno)
   45: {
   46:         FILE *fp;
   47:         int f;
   48:         int flags, oflags;
   49: 
   50:         if ((flags = __sflags(mode, &oflags)) == 0)
   51:                 { f = EINVAL; goto e1; }
   52:         if ((fp = __sfp()) == NULL)
   53:                 { f = EMFILE; goto e1; }
   54:         if ((f = __libc_open(file, oflags, DEFFILEMODE)) < 0) {
   55:                 fp->_flags = 0;                       /* release */
   56:                 f &= 0xffff; goto e1;
   57:         }
   58: 
   59:         /* _file is only a short */
   60:         if (f > SHRT_MAX) {
   61:                 fp->_flags = 0;                       /* release */
   62:                 __libc_close(f);
   63:                 /*errno*/f = EMFILE;
   64:                 goto e1;
   65:         }
   66: 
   67:         fp->_file = f;
   68:         fp->_flags = flags;
   69:         fp->_cookie = fp;
   70:         fp->_read = __sread;
   71:         fp->_write = __swrite;
   72:         fp->_seek = __sseek;
   73:         fp->_close = __sclose;
   74: 
   75:         /*
   76:          * When opening in append mode, even though we use O_APPEND,
   77:          * we need to seek to the end so that ftell() gets the right
   78:          * answer.  If the user then alters the seek pointer, or
   79:          * the file extends, this will fail, but there is not much
   80:          * we can do about this.  (We could set __SAPP and check in
   81:          * fseek and ftell.)
   82:          */
   83:         if (oflags & O_APPEND)
   84:                 (void) __sseek((void *)fp, (fpos_t)0, SEEK_END);
   85:         return (fp); e1: if (eno) *eno = f; return NULL;
   86: }
   87: FILE *fopen(const char *path, const char *mode){ return fopen_eno(path, mode, NULL); }