Practical Programming in Tcl & Tk, Third Edition

Hidden Commands

The commands listed in Table 19-2 are hidden instead of being completely removed. A hidden command can be invoked in a slave by its master. For example, a master can load Tcl scripts into a slave by using its hidden source command:

interp create -safe slave
interp invokehidden slave source filename
					

Without hidden commands, the master has to do a bit more work to achieve the same thing. It must open and read the file and eval the contents of the file in the slave. File operations are described in Chapter 9.

interp create -safe slave
set in [open filename]
interp eval slave [read $in]
close $in

Hidden commands were added in Tcl 7.7 in order to better support the Tcl/Tk browser plug-in described in Chapter 20. In some cases, ...