.\"Copyright 2010 (c) EPFL
.TH XDF_SEEK 3 2010 "EPFL" "xdffileio library manual"
.SH NAME
xdf_seek - move the sample pointer of a xDF file
.SH SYNOPSIS
.LP
.B #include <xdfio.h>
.sp
.BI "off_t xdf_seek(struct xdf* " xdf ", off_t " offset ", int " whence ");"
.br
.SH DESCRIPTION
.LP
\fBxdf_seek\fP() repositions the current sample pointer according to the
couple (\fIoffset\fP,\fIwhence\fP) where \fIwhence\fP can be:
.TP 7
.B SEEK_SET
The offset is set to \fIoffset\fP bytes.
.TP 7
.B SEEK_CUR
The offset is set to its current location plus \fIoffset\fP bytes.
.TP 7
.B SEEK_END
The offset is set to the size of the file plus \fIoffset\fP bytes.
.LP
The file referenced by \fIxdf\fP should have been opened with mode
\fBXDF_READ\fP and \fBxdf_prepare_arrays\fP(3) should have been successfully
called on it.
.SH "RETURN VALUE"
.LP
Upon successful completion, \fBxdf_seek\fP() returns the resulting offset
location as measured in number of samples from the beginning of the
recording. Otherwise, a value of \-1 is returned and \fIerrno\fP is set to
indicate the error.
.SH ERRORS
.TP 7
.B EINVAL
\fIxdf\fP is NULL or \fIwhence\fP is none of the allowed values.
.TP 7
.B EPERM
No successfull call to \fBxdf_prepare_transfer\fP(3) have been done on
\fIxdf\fP or it has been opened using the mode \fBXDF_WRITE\fP.
.TP 7
.B ERANGE
The requested offset is out of the range of the recording.
.TP 7
.B EINTR
The call was interrupted by a signal before any data was read; see
\fBsignal\fP(7).
.TP 7
.B EIO
A low-level I/O error occurred while reading from the inode.
.TP 7
.B ESTALE
Stale file handle. This error can occur for NFS and for other file systems
.SH "SEE ALSO"
.BR xdf_define_arrays (3),
.BR xdf_prepare_transfer (3)