gonzui

    1: /*      $OpenBSD: stdio.c,v 1.9 2005/08/08 08:05:36 espie 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 <fcntl.h>
   35: #include <unistd.h>
   36: #include <stdio.h>
   37: #include "local.h"
   38: 
   39: /*
   40:  * Small standard I/O/seek/close functions.
   41:  * These maintain the `known seek offset' for seek optimisation.
   42:  */
   43: int
   44: __sread(void *cookie, char *buf, int n)
   45: {
   46:         FILE *fp = cookie;
   47:         int ret;
   48:         
   49:         ret = __libc_read(fp->_file, buf, n);
   50:         /* if the read succeeded, update the current offset */
   51:         if (ret >= 0)
   52:                 fp->_offset += ret;
   53:         else
   54:                 {fp->_flags &= ~__SOFF; __sseterr(fp, ret); ret = -1; }       /* paranoia */
   55:         return (ret);
   56: }
   57: 
   58: int
   59: __swrite(void *cookie, const char *buf, int n)
   60: {
   61:         FILE *fp = cookie;
   62:         int    ret;
   63: 
   64:         if (fp->_flags & __SAPP)
   65:                 (void) __libc_lseek(fp->_file, (off_t)0, SEEK_END);
   66:         fp->_flags &= ~__SOFF; /* in case FAPPEND mode is set */
   67:         ret = __libc_write(fp->_file, buf, n);
   68:         if (ret < 0) { __sseterr(fp, ret); ret = -1; }
   69:         return ret;
   70: }
   71: 
   72: fpos_t
   73: __sseek(void *cookie, fpos_t offset, int whence)
   74: {
   75:         FILE *fp = cookie;
   76:         off_t ret;
   77:         
   78:         ret = __libc_lseek(fp->_file, (off_t)offset, whence);
   79:         if (/*ret == (off_t)-1)*/ret < 0) __sseterr(fp, (int)ret), ret = -1, fp->_flags |= __SERR,
   80:                 fp->_flags &= ~__SOFF;
   81:         else {
   82:                 fp->_flags |= __SOFF;
   83:                 fp->_offset = ret;
   84:         }
   85:         return (ret);
   86: }
   87: 
   88: int
   89: __sclose(void *cookie)
   90: {
   91:         int ret = __libc_close(((FILE *)cookie)->_file); if (ret < 0) { __sseterr((FILE *)cookie, ret); return -1; } return 0;
   92: }