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/**
* \file seek.c
*
* \brief Segment seek routines.
*
* This program is free software under the GNU General Public License
* (>=v2). Read the file COPYING that comes with GRASS for details.
*
* \author GRASS GIS Development Team
*
* \date 2005-2006
*/
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <grass/config.h>
#include <grass/gis.h>
#include <grass/segment.h>
/**
* \fn int segment_seek (SEGMENT *SEG, int n, int index)
*
* \brief Seek into a segment.
*
* \param[in,out] SEG segment
* \param[in] n
* \param[in] index
* \return 0 on success
* \return -1 if unable to seek
*/
int segment_seek(const SEGMENT * SEG, int n, int index)
{
off_t offset;
offset = (off_t) n *SEG->size + index + SEG->offset;
if (lseek(SEG->fd, offset, SEEK_SET) == (off_t) - 1) {
G_warning("segment_seek: %s", strerror(errno));
return -1;
}
return 0;
}
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