tmpfile() [system call]

#include <stdio.h>
FILE *tmpfile(void);
example
#include <stdio.h>
FILE *stream;
char tmpstring[ ] = "This is the string to be temporarily written";
int main(void)
{
if ((stream = tmpfile( )) == NULL)
perror("Cannot make a temporary file");
else
fprintf(stream, "%s", tmpstring);
}