You may heared about reserved words in progrmming language, reserved words are terms or phrases appropriated for special use that may not be utilized in the creation of variable names. For example, “print” is a reserved word because it is a function in many languages to show text on the screen.
Did you know that there are some words in windows that you cannot use? Here’s what you will do, try to create a folder and rename it to CON or AUX, what you’ll see is when you hit enter, the folder name will revert back to “New Folder”. The reason? this are reserved words. Reserved words are widely used during the DOS era and didn’t change those properties until now. Here are the Windows reserved words:
Here i am going to explain why you can not create the con folder in windows.
We can not create folder using these reserved words.So if we are allowed to create such folder, then there will be an ambiguity in where to write data when the data is supposed to go to the specified devices.
For Example :- If i want to print something, internally what windows does is — it will write the data to the folder prn (virtually u can call it a folder, i mean prn, con, etc are virtual folders in device level). So if we are able to create con folder, windows will get confused where to write the data, to virtual con folder or real one.
Keywords and Their corresponding Functions:
Reserved Keywords Function
CON Keyboard and Display
PRN System list device, usually a parellel port
AUX Auxiliary Device,usually a serial port
NUL Bit-Bucket Device
A:-Z: Drive Letter
COM1 First Serial communications port
COM2 Second Serial communications port
COM3 Third Serial communications port
COM4 Fourth Serial communications port
LPT1 First Parallel printer port
LPT2 second Parallel printer port
LPT3 Third Parallel printer port