diff options
Diffstat (limited to 'tools/cpio/src/ib_seek.c')
| -rw-r--r-- | tools/cpio/src/ib_seek.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/tools/cpio/src/ib_seek.c b/tools/cpio/src/ib_seek.c new file mode 100644 index 000000000..48b2f99bc --- /dev/null +++ b/tools/cpio/src/ib_seek.c @@ -0,0 +1,53 @@ +/* + * 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; +} |