_splitpath giving me errors!

[Kixdemp]

Hello everyone!
Alright. Why does my program crash after this line?

char * getPartName(char * fileName, int part)
{
    char *newName;
    
    _splitpath("C:\\Documents and Settings\\Kixdemp\\Desktop\\Mythax\\screenshot.png", NULL, NULL, newName, NULL); // << This one
    
    printf("Checkpoint!");
    
    printf(newName);
    
    return newName;
}

I get a "mythax.exe has encountered a problem and needs to close. We are sorry for the inconvenience." error... Why is it? Thanks!

BTW: Also, _splitpath is cross-platform, not just Windows, right? And, does the path have to be full? What if the user enters just a filename in the command line? (A file that's on the same dir.)

[Salem]

> Why does my program crash after this line?
- You didn't allocate space for your pathname

char newName[100];
Would be an improvement (just), but then you have the problem of returning a pointer to a local variable.

static char newName[100];
Is a bit better, but you can't call the function twice without trashing the result of the first call.

It's generally best if the caller supplies a parameter of where to put the result.

> printf(newName);
- The result contains a %, which then blows up your poor use of printf() ?
Never pass an unknown or user string to printf() as the control string. Any % in there will blow up big time.
Use printf("%s\n", newName );



> _splitpath is cross-platform, not just Windows, right?
No it isn't.

[Kixdemp]

>> _splitpath is cross-platform, not just Windows, right?
> No it isn't.

Oh, forget it then... Is there any other way of retrieving a filename without the extension? Thanks!

[hk_mp5kpdw]

>> _splitpath is cross-platform, not just Windows, right?
> No it isn't.

Oh, forget it then... Is there any other way of retrieving a filename without the extension? Thanks!

Parse the data yourself. Figure out what you need to search for in the original path string to get only the filename and create a new buffer (or use one passed into the function) to store/return the necessary data.

[Kixdemp]

Hmm... Yeah, I've tried that, but it didn't work... Then I tried _splitpath(), but since that isn't cross-platform, I'll have to try the former again. Thanks!

[edit] Forget that! Too much damn work. I'll just have the user optionally select a name in the command line, and if they don't, then I'll just try to add the extension to the filename. [/edit]

[Salem]

> Is there any other way of retrieving a filename without the extension?
1. The whole world doesn't use \ as a separator, many other popular OS'es use /
2. you can use strrchr() to find the last instance of a char in a string, which is useful for finding where the path ends and the filename starts.

[wannolearnc]

My comments are in red.

char * getPartName(char * fileName, int part)
{
    char *newName;

newName not allocated!
    
    _splitpath("C:\\Documents and Settings\\Kixdemp\\Desktop\\Mythax\\screenshot.png  ", NULL, NULL, newName, NULL); // << This one
    
    printf("Checkpoint!");
    
    printf(newName);
    
    return newName;

ERR returning a local variable!!
}

[quzah]

You do know you can return pointers, right? How the hell do you think malloc works?


Quzah.

[wannolearnc]

1) What does 'newName' point to ? Its a local pointer....not pointing to any valid address up the stack!!
2) If you return it and reference it outside this function your code will crash!!

[Salem]

> 1) What does 'newName' point to ? Its a local pointer....not pointing to any valid address up the stack!!
True, but it doesn't have to point to stack memory.
newName = malloc( 100 );
would fix that problem.

> 2) If you return it and reference it outside this function your code will crash!!
It's already broken because it's unallocated, not because it's returned. If it's pointing to valid memory (say via malloc), then returning the pointer is just fine.