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/* Copyright (C) 1991, 1992, 1996, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/uio.h>
/* Read data from file descriptor FD, and put the result in the
buffers described by VECTOR, which is a vector of COUNT `struct iovec's.
The buffers are filled in the order specified.
Operates just like `read' (see <unistd.h>) except that data are
put in VECTOR instead of a contiguous buffer. */
ssize_t
__readv (fd, vector, count)
int fd;
const struct iovec *vector;
int count;
{
char *buffer;
size_t bytes;
int bytes_read;
int i;
/* Find the total number of bytes to be read. */
bytes = 0;
for (i = 0; i < count; ++i)
bytes += vector[i].iov_len;
/* Allocate a temporary buffer to hold the data. */
buffer = (char *) __alloca (bytes);
/* Read the data. */
bytes_read = __read (fd, buffer, bytes);
if (bytes_read <= 0)
return -1;
/* Copy the data from BUFFER into the memory specified by VECTOR. */
bytes = bytes_read;
for (i = 0; i < count; ++i)
{
#define min(a, b) ((a) > (b) ? (b) : (a))
size_t copy = min (vector[i].iov_len, bytes);
(void) memcpy ((void *) vector[i].iov_base, (void *) buffer, copy);
buffer += copy;
bytes -= copy;
if (bytes == 0)
break;
}
return bytes_read;
}
#ifndef __readv
weak_alias (__readv, readv)
#endif
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