C preprocessor: removing quotes from an argument
I'm abusing the C preprocessor for my build system to produce a "readme" plain-text file and a web page from the same source file. The construction is something like this:
The actual definitions are in data.h
:
#define WEBSITE "http://example.com"
Note that the //
in the URL must be quoted, or else it will be treated as the start of a comment. A similar problem occurs when using a ,
in the argument; the quotes are necessary, or else the comma would be treated as an argument separator.
Using this header, a file readme.txt.pp
is run through the C preprocessor:
#include "data.h"
Visit the website at WEBSITE!
Of course, the preprocessor output is:
Visit the website at "http://example.com"!
The quotes appear in the output. Is there any way, or workaround, to get this code to give the output:
Visit the website at http://example.com!
I'm using Visual C++ 2008. I know that the preprocessor is not the ideal tool for this job; suggestions that use other built-in VC++ features are also welc开发者_JS百科ome. (I tried XML with XSLT, but it is impossible to include one XML file into another, which was a show-stopper.)
Regarding XSLT, have a look at the document()
function to read from multiple source documents.
I don't think there's any way to remove the quotes from the value of WEBSITE
, since they are there in the definition of the macro. You might consider using the m4
macro processor instead of the C preprocessor.
Probably being late for Thomas, this might, however, still be useful for anyone lately stumbling over this question like me...
Try this:
#define DUMMY
#define WEBSITE http:/DUMMY/example.com
So the line comment disappears, and the preprocessor resolves DUMMY to nothing.
Try disabling the C++ style comments if possible. I don't know how that works in VS, but using a GCC compiler I can pass the -std=c89
flag to gcc to disable C++ style comments and hence making
#define WEBSITE http://example.com
possible.
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