(1) To engage a file for reading and writing. The open procedure "locks on" to an existing file. Very often, the term "open" is used to mean "open and run," in which case if the file is a script of some type, it will be executed, not just opened for examination. In some cases, the difference can be critical. Opening a batch file to view its contents is harmless, whereas opening a batch file and running it causes actions to be taken. Contrast with close.|
(2) With regard to a switch, open is "off." See switch.