Generating a Unique Filename

 
char * tmpnam(char * name);

The function generates a unique name that may contain up to L_tmpnam characters. You can call tmpnam() up to TMP_MAX (the TMP_MAX and L_tmpnam constants are defined in <stdio.h>) times without generating repeated names. For example:

 
#include <cstdio>
#include <iostream>
using namespace std;
int main()
{
 char name[L_tmpnam];
 for (int n=0; n<TMP_MAX; ++n)
 {
  tmpnam(name);
  cout << name << endl;
 }
}