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/*
* Copyright (c) 2003 Gunnar Ritter
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute
* it freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any source distribution.
*/
/* Sccsid @(#)ib_seek.c 1.4 (gritter) 5/8/03 */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include "iblok.h"
off_t
ib_seek(struct iblok *ip, off_t off, int whence)
{
if (whence == SEEK_CUR) {
off = ip->ib_endoff - (ip->ib_end - ip->ib_cur);
whence = SEEK_SET;
}
if (ip->ib_seekable && whence == SEEK_SET && ip->ib_cur && ip->ib_end &&
off < ip->ib_endoff &&
off >= ip->ib_endoff - (ip->ib_end - ip->ib_blk)) {
ip->ib_cur = ip->ib_end - (ip->ib_endoff - off);
return off;
}
if ((off = lseek(ip->ib_fd, off, whence)) == (off_t)-1)
return -1;
ip->ib_cur = ip->ib_end = NULL;
ip->ib_endoff = off;
ip->ib_seekable = 1;
return off;
}
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