gotoLine ?-w win? ?row?
If row is specified, the command sets the current position to the beginning of this row and makes it visible. If the value of row is greater than the number of lines in the document, the command jumps to the beginning of the last line.
When no row argument is specified, the command is meant for asynchronous use: it prompts for a line in the specified window and jumps to it (equivalent to clicking on the row indicator at the bottom of the window). When run asynchronously, this command returns immediately and should not be used in a Tcl script.