Dialogs for choosing a file to open and save
popup_open_file(multiple, ...)
popup_save_file(confirmoverwrite, ...)allow the user to choose multiple files? default: FALSE
other arguments. See tcltk documentation for all possible options
If user selects a filename which already exists, then show another popup to confirm overwriting this file. Default: TRUE.
See tcl/tk documentation for more information on this element https://www.tcl.tk/man/tcl8.6/TkCmd/getOpenFile.html