How to input special character in cmd?

Question

I have written a c program that retrieves arguments from the command line under Windows. One of the arguments is a regular expression. So I need to retrieve special characters such as "( , .", etc., but cmd.exe treats "(" as a special character.

How could I input these special character?

thanks.

Answer 1

You can generally prefix any character with ^ to turn off its special nature. For example:

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Pax>echo No ^<redirection^> here and can also do ^
More? multi-line, ^(parentheses^) and ^^ itself
No <redirection> here and can also do multi-line, (parentheses) and ^ itself

C:\Documents and Settings\Pax>

That's a caret followed by an ENTER after the word do.

Answer 2

You can put the arguments in quotes:

myprogram.exe "(this is some text, with special characters.)"

Though I wouldn't assume that parentheses cause problems unless you are using blocks for conditional statements or loops in a batch file. The usual array of characters that are treated specially by the shell and need quoting or escaping are:

& | > < ^

If you use those in your regular expression, then you need quotes, or escape those characters:

myprogram "(.*)|[a-f]+"
myprogram (.*)^|[a-f]+

(^ is the escape character which causes the following character to be not interpreted by the shell but instead used literally)