help with warnings/and C stuff

[sitko]

Hi,

I'm still working on my VB->C conversion program, and am now struggling with Segmenation Fault errors.

This question isn't about that. I'm also getting some warnings regarding some calls of strrchr I'm doing. I got my current understanding of strrchr from the website cplusplus.com, specifically:
http://www.cplusplus.com/reference/c...g/strrchr.html

Their code is as follows:

char str[] = "This is a sample string";
  char * pch;
  pch=strrchr(str,'s');
  printf ("Last occurence of 's' found at %d \n",pch-str+1);
  return 0;
 

My code is as follows:

char * pch;
....
#if _WIN32
    {
        pch=strrchr(gstrBottleFile,"\\");  //could I pass it char(92) instead?
    }
#else
    {
        pch=strrchr(gstrBottleFile,"/"); //could I pass it char(47) instead?
    }
#endif
 

The else statment gives me the following error when I compile this on Linux:
"warning: passing arg 2 of `strrchr' makes integer from pointer without a cast".

I basically hoping that someone can explain to me why this is happening, as its a warning, I decided to ignore it for now, but am still curious why this warning keeps popping up. And why only on the Linux side, and not the windows side as well.

Thanks,
Sitko.

[weaknessforcats]

The second argument of strrchr() is a character. Not a string.

Try single quotes.

[sitko]

Thanks,
That did the trick. Just for the unix line, not the other, as it has two slashes (to dereference the slash).

As to the pch being a char instead of a pointer, later in the code I 'use' it as a string, in this debug statement:
//printf("%s , %s\n",gstrBottleFile,(pch+1));
and it works to print out everything AFTER the last slash...

Thanks again for the quick turnaround...

Are there any good references regarding identifying the cause of a segmatation fault error?

Thanks,
Sitko.

[oler1s]

A good guess for a segfault is bad memory access. So you basically find the lines of code causing a segfault and see what memory is accessed.

By bad memory access, I mean things like going out of arrays (once out of the array, you are trying to read/write memory that isn't yours), bad pointers, and that sort of thing.

[sitko]

A good guess for a segfault is bad memory access. So you basically find the lines of code causing a segfault and see what memory is accessed.

By bad memory access, I mean things like going out of arrays (once out of the array, you are trying to read/write memory that isn't yours), bad pointers, and that sort of thing.

I did make some good progress on this issue, by bounding my string variables (character arrays). In the examples I've been referring to, they often just put" "char * Var", and apparently this isn't "liked" by the linux compliler, so I switch them to char Var[200]; and the segfaults moved further downstream...

Thanks,
Sitko.

[weaknessforcats]

That did the trick. Just for the unix line, not the other, as it has two slashes (to dereference the slash).

\\ is one char. That is, '\\'.

Remember, the \ is an escape sequence and it indicates that the symbol folllowing is a code. \\ is the \ character. It's the only way you can code it.

Dereference is used with respect to pointers.