44 lines
1.3 KiB
C
44 lines
1.3 KiB
C
/*
|
|
* Copyright (c) 2012, 2013, 2015 Jonas 'Sortie' Termansen.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* ioleast/readleast.c
|
|
* Reads at least as much data as requested or more.
|
|
*/
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <ioleast.h>
|
|
#include <stdint.h>
|
|
#include <unistd.h>
|
|
|
|
size_t readleast(int fd, void* buf_ptr, size_t least, size_t max)
|
|
{
|
|
assert(least <= max);
|
|
unsigned char* buf = (unsigned char*) buf_ptr;
|
|
size_t done = 0;
|
|
do
|
|
{
|
|
ssize_t amount = read(fd, buf + done, max - done);
|
|
if ( amount < 0 )
|
|
return done;
|
|
if ( !amount && done < least )
|
|
return errno = EEOF, done;
|
|
if ( !amount )
|
|
break;
|
|
done += amount;
|
|
} while ( done < least );
|
|
return done;
|
|
}
|