Annotation of prex/usr/lib/libc/stdio/fread.c, Revision 1.1
1.1 ! nbrk 1: /*-
! 2: * Copyright (c) 1990, 1993
! 3: * The Regents of the University of California. All rights reserved.
! 4: *
! 5: * This code is derived from software contributed to Berkeley by
! 6: * Chris Torek.
! 7: *
! 8: * Redistribution and use in source and binary forms, with or without
! 9: * modification, are permitted provided that the following conditions
! 10: * are met:
! 11: * 1. Redistributions of source code must retain the above copyright
! 12: * notice, this list of conditions and the following disclaimer.
! 13: * 2. Redistributions in binary form must reproduce the above copyright
! 14: * notice, this list of conditions and the following disclaimer in the
! 15: * documentation and/or other materials provided with the distribution.
! 16: * 3. Neither the name of the University nor the names of its contributors
! 17: * may be used to endorse or promote products derived from this software
! 18: * without specific prior written permission.
! 19: *
! 20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 30: * SUCH DAMAGE.
! 31: */
! 32:
! 33: #include <stdio.h>
! 34: #include <string.h>
! 35: #include "local.h"
! 36:
! 37: size_t
! 38: fread(buf, size, count, fp)
! 39: void *buf;
! 40: size_t size, count;
! 41: FILE *fp;
! 42: {
! 43: size_t resid;
! 44: char *p;
! 45: int r;
! 46: size_t total;
! 47:
! 48: /*
! 49: * The ANSI standard requires a return value of 0 for a count
! 50: * or a size of 0. Peculiarily, it imposes no such requirements
! 51: * on fwrite; it only requires fread to be broken.
! 52: */
! 53: if ((resid = count * size) == 0)
! 54: return (0);
! 55: if (fp->_r < 0)
! 56: fp->_r = 0;
! 57: total = resid;
! 58: p = buf;
! 59: while (resid > (size_t)(r = fp->_r)) {
! 60: (void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
! 61: fp->_p += r;
! 62: /* fp->_r = 0 ... done in __srefill */
! 63: p += r;
! 64: resid -= r;
! 65: if (__srefill(fp)) {
! 66: /* no more input: return partial result */
! 67: return ((total - resid) / size);
! 68: }
! 69: }
! 70: (void)memcpy((void *)p, (void *)fp->_p, resid);
! 71: fp->_r -= resid;
! 72: fp->_p += resid;
! 73: return (count);
! 74: }
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