public override long Seek(long offset, SeekOrigin origin)
{
AssertNotDisposed();
if (!CanSeek)
{
throw new NotSupportedException("The File Descriptor does not support seeking");
}
Native.SeekFlags sf = Native.SeekFlags.SEEK_CUR;
switch (origin)
{
case SeekOrigin.Begin: sf = Native.SeekFlags.SEEK_SET; break;
case SeekOrigin.Current: sf = Native.SeekFlags.SEEK_CUR; break;
case SeekOrigin.End: sf = Native.SeekFlags.SEEK_END; break;
}
long pos = Native.Syscall.lseek(fileDescriptor, offset, sf);
if (pos == -1)
{
UnixMarshal.ThrowExceptionForLastError();
}
return((long)pos);
}
public override long Seek(long offset, SeekOrigin origin)
{
AssertNotDisposed();
if (!CanSeek)
{
throw new NotSupportedException("The File Stream does not support seeking");
}
Native.SeekFlags sf = Native.SeekFlags.SEEK_CUR;
switch (origin)
{
case SeekOrigin.Begin:
sf = Native.SeekFlags.SEEK_SET;
break;
case SeekOrigin.Current:
sf = Native.SeekFlags.SEEK_CUR;
break;
case SeekOrigin.End:
sf = Native.SeekFlags.SEEK_END;
break;
default:
throw new ArgumentException("origin");
}
int r = Native.Stdlib.fseek(file, offset, sf);
if (r != 0)
{
throw new IOException("Unable to seek",
UnixMarshal.CreateExceptionForLastError());
}
long pos = Native.Stdlib.ftell(file);
if (pos == -1)
{
throw new IOException("Unable to get current file position",
UnixMarshal.CreateExceptionForLastError());
}
GC.KeepAlive(this);
return(pos);
}
