Developing and Porting C and C++ Applications on AIX

7.2. Using the printf()-debug method

The printf()-debug method is easy to understand and is still the most common method used to debug applications. To use the method, define the following macro in your codes:

#if !defined(DEBUG)
#define DBGMSG(MSGSTR) ((void)0)
#else
#define DBGMSG(MSGSTR) {\
        fprintf(stderr,"In %s() at line %d in file %s: %s"\
                , __FUNCTION__, __LINE__, __FILE__, (MSGSTR));\
        }
#endif

then call this macro where you would like to print messages, for example:

int main(int argc, char *argv[])
{
    DBGMSG("Hi there!\n");
    exit(0);
}

If you compile the source code with the -DDEBUG compiler option,then it will print a debug message very similar to the following line:

In main() at line 16 in file printf-debug.c: Hi there!

Although ...