How to return the size and name of largest file in a directory hierachy....

Return a structure...

struct sizedFile {
  unsigned int length ;
  char pathName[8000] ;
}

it works....  but involves copying a lot of data...

What about return a pointer to the structure!

struct sizedFile *biggestFile(....) {
  struct sizeFile biggestFileRet ;
  ...
  ...
  return &biggestFileRet ;
}

But returning a pointer to data on the stack which will be reused!

a CSCI 335 topic and Java-like solution

struct sizedFile *biggestFile(....) {
  struct sizeFile *biggestFilePtr = (struct sizeFile *)malloc(sizeof(struct sizeFile) ;
  ....
  return biggestFilePtr ;
}

But most of these returns will *not* be used! Lots of inaccessable memory.

The solution -- You only need to keep up with the largest file!
Use free(...), but be careful!
This is for CSCI 335.

**** Java and Python use garbage collection to avoid this problem.

Let's take the low path.  Have the caller allocate the buffer!
A bit like file I/O in C!

unsigned int biggestFile(...., char *biggestPathName) {
  struct sizeFile forTheChild ;
  ....
  .... calls
    size = biggestFile(forTheChild) ;
    ... get the size and fill in the name
}

No malloc() [dynamic memory].  All data on the stack is in use.

One problem: How do we indicate the directory contains no file?

Check the return value?
   Is it zero?      Nope, the largest file may be of size 0.
   Use -1 as flag?  Nope, -1 in not an unsigned int.
   Set pathName to start with '\0'?  That should work


    if (forTheChild[0]) {
        size = biggestFile(forTheChild) ;
	if (size>biggestSoFarSize) ....
    }