Programming

Code:

#define _XOPEN_SOURCE 1
#include <stdio.h>  
#include <stdlib.h>   

FILE * my_tester (char * fname, int pnum) 
{   
  int fd;   
  FILE * fp;      
    sprintf (fname, "/tmp/PRS.%05i.XXXXXX", pnum);         
    fd = mkstemp (fname);     
    if (fd <0) 
    {    
         return (NULL); 
    }         
    if ((fp = fdopen (fd, "w")) == NULL)     
    {         
        return (NULL);     
    }
     return (fp); 
}

Note that defining the feature test macro _xopen_source to have the value 1 as done by the following line in dodona's code in post #5 (and later duplicated in HongThai's code in post #8) as shown below:

Code:

#define  _XOPEN_SOURCE  1

without defining any other feature test macros asks for a programming environment that conforms to the interfaces as defined by The X/Open Portability Guide, Issue 3 (which was published in 1988). The only systems that I'm aware of that still support this programming environment are Solaris/SunOS systems distributed by Sun, Oracle, and Fujitsu.

The feature test macro I suggested in post #3 requests a much more commonly available programming environment.