#include <string>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/wait.h>

bool isprogram(string str)
{ FILE * f=fopen("temp.cpp", "w");
  fprintf(f, str.c_str());
  fclose(f);

  int s, p=fork();
  if (p==0)
  { close(2);
    open("/dev/null", O_WRONLY);
    execlp("/usr/bin/CC", "CC", "temp.cpp", "-o", "temp", NULL);
    printf("Should never get here\n"); }

  p=wait(&s);
  return (s==0); }

























void main()
{ string s1 = "#include <stdio.h>\n\nvoid main()\n{ printf(\"Go away!\\n\"); }\n\n";
  string s2 = "#include <stdio.h>\n\nvoid main()\n{ printf(\"Go away!\\n\"); @ }\n\n";

  bool ok=isprogram(s1);
  if (ok)
    printf("s1 is a program\n");
  else
    printf("s1 is NOT a program\n");

  ok=isprogram(s2);
  if (ok)
    printf("s2 is a program\n");
  else
    printf("s2 is NOT a program\n"); }