Using C preprocessor to construct a string literal for scanf?

Posted by Brett on Stack Overflow See other posts from Stack Overflow or by Brett
Published on 2010-04-29T19:05:37Z Indexed on 2010/04/29 19:07 UTC
Read the original article Hit count: 296

Filed under:

concatenation

I'm attempting to create an sscanf string literal to aid in buffer overrun prevention in C99. The goal is something like:

#define MAX_ARG_LEN   16

char arg[MAX_ARG_LEN] = "";

if (sscanf(arg, "%"(MAX_ARG_LEN-1)"X", &input) > 0)

The obvious "manual" solution is something like:

#define MAX_ARG_LEN   16
#define MAX_ARG_CHARS "15"

char arg[MAX_ARG_LEN] = "";

if (sscanf(arg, "%"MAX_ARG_CHARS"X", &input) > 0)

However, I would prefer something to automatically generate "%15X" given a buffer size of 16. This link is almost works for my application: http://stackoverflow.com/questions/240353/convert-a-preprocessor-token-to-a-string but it does not handle the -1.

Suggestions?

Related posts about preprocessor

Any other preprocessor directives in VBScript/Classic ASP?

as seen on Stack Overflow - Search for 'Stack Overflow'
The only pre-process directive that I know about in VBScript / Classic ASP is the #include. I don't know if that is the official name but I'm basically looking for code that can execute code or other instructions before the general VBScript. Are there any other such directives in VBScript? Such as… >>> More
Visual Studio 2008 Preprocessor wierdness

as seen on Stack Overflow - Search for 'Stack Overflow'
We have set-up a simple versioning system for our builds to ensure the built files always indicate whether they are Beta Debug or Beta Release builds I moved the file version info to to myapp.rc2 and created version.h // version.h // _DEBUG is defined by VS #define _BETA #ifdef… >>> More
Writing preprocessor directives to get string

as seen on Stack Overflow - Search for 'Stack Overflow'
Can you write preprocessor directives to return you a std::string or char*? For example: In case of integers: #define square(x) (x*x) int main() { int x = square(5); } I'm looking to do the same but with strings like a switch-case pattern. if pass 1 it should return "One" and 2 for "Two" so… >>> More
Are preprocessors obsolete in modern languages?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello, I'm making a simple compiler for a simple pet language I'm creating and coming from a C background(though I'm writing it in Ruby) I wondered if a preprocessor is necessary. What do you think? Is a "dumb" preprocessor still necessary in modern languages? Would C#'s conditional compilation capabilities… >>> More
The Bizarre Hidden Powers of the Preprocessor? [closed]

as seen on Stack Overflow - Search for 'Stack Overflow'
The preprocessor in C and C++ deserves an entire essay on its own to explore its rich possibilities for obfuscation. It is true that the C++ (and C) preprocessor can be used for a lot of powerful stuff. #ifdefs and #defines are often used to determine platforms, compilers and backends. Manipulating… >>> More

Developer IT

Using C preprocessor to construct a string literal for scanf? - Developer IT

Using C preprocessor to construct a string literal for scanf?

c

preprocessor

string

literal

concatenation

Related posts about c

Related posts about preprocessor

Any other preprocessor directives in VBScript/Classic ASP?

Visual Studio 2008 Preprocessor wierdness

Writing preprocessor directives to get string

Are preprocessors obsolete in modern languages?

The Bizarre Hidden Powers of the Preprocessor? [closed]

Categories cloud