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