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- /*
- (C) 1995-96 AROS - The Amiga Replacement OS
- $Id: seek.c,v 1.3 1996/08/13 13:52:51 digulla Exp $
- $Log: seek.c,v $
- Revision 1.3 1996/08/13 13:52:51 digulla
- Replaced <dos/dosextens.h> by "dos_intern.h" or added "dos_intern.h"
- Replaced __AROS_LA by __AROS_LHA
-
- Revision 1.2 1996/08/01 17:40:57 digulla
- Added standard header for all files
-
- Desc:
- Lang: english
- */
- #include <clib/exec_protos.h>
- #include <dos/filesystem.h>
- #include "dos_intern.h"
-
- /*****************************************************************************
-
- NAME */
- #include <clib/dos_protos.h>
-
- __AROS_LH3(LONG, Seek,
-
- /* SYNOPSIS */
- __AROS_LHA(BPTR, file, D1),
- __AROS_LHA(LONG, position, D2),
- __AROS_LHA(LONG, mode, D3),
-
- /* LOCATION */
- struct DosLibrary *, DOSBase, 11, Dos)
-
- /* FUNCTION
- Changes the actual read/write position in a file and/or
- reads the actual position, e.g to get the actual position
- do a Seek(file,0,OFFSET_CURRENT).
-
- This function may fail (obviously) on certain devices such
- as pipes or console handlers.
-
- INPUTS
- file - filehandle
- position - relative offset in bytes (positive, negative or 0).
- mode - Where to count from. Either OFFSET_BEGINNING,
- OFFSET_CURRENT or OFFSET_END.
-
- RESULT
- Absolute position in bytes before the Seek(), -1 if an error
- happened. IoErr() will give additional information in that case.
-
- NOTES
-
- EXAMPLE
-
- BUGS
-
- SEE ALSO
-
- INTERNALS
-
- HISTORY
- 29-10-95 digulla automatically created from
- dos_lib.fd and clib/dos_protos.h
-
- *****************************************************************************/
- {
- __AROS_FUNC_INIT
- __AROS_BASE_EXT_DECL(struct DosLibrary *,DOSBase)
-
- /* Get pointer to filehandle */
- struct FileHandle *fh=(struct FileHandle *)BADDR(file);
-
- /* Get pointer to process structure */
- struct Process *me=(struct Process *)FindTask(NULL);
-
- /* Get pointer to I/O request. Use stackspace for now. */
- struct IOFileSys io,*iofs=&io;
-
- /* Prepare I/O request. */
- iofs->IOFS.io_Message.mn_Node.ln_Type=NT_REPLYMSG;
- iofs->IOFS.io_Message.mn_ReplyPort =&me->pr_MsgPort;
- iofs->IOFS.io_Message.mn_Length =sizeof(struct IOFileSys);
- iofs->IOFS.io_Device =fh->fh_Device;
- iofs->IOFS.io_Unit =fh->fh_Unit;
- iofs->IOFS.io_Command=FSA_SEEK;
- iofs->IOFS.io_Flags =0;
- iofs->io_Args[0]=position<0?-1:0;
- iofs->io_Args[1]=position;
- iofs->io_Args[2]=mode;
-
- /* Send the request. */
- DoIO(&iofs->IOFS);
-
- /* return */
- if((me->pr_Result2=iofs->io_DosError))
- return -1;
- else
- return iofs->io_Args[1];
- __AROS_FUNC_EXIT
- } /* Seek */
-