/* * 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; }