problem using dup2()

[talal*c]

hi guys..

i have this problem with using dub2()

i whant to semuliate the unix shell like "prog1 > file.out"

this code is for that but it dose not work
i used linked list functions and i am sure that it is correct.
the parsing is working good ethier.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include "linklist.h"


int read_cmd();
ptr list; 
	

int main()
{
	read_cmd();

	return 0;
}

int read_cmd()
{
	char com[100];
	int i = 0, j = 0, len;
	datatype buffer;
	pid_t pid, status;
	ptr f, o, s;
	static char *argv[] = { "ps", "f", NULL};


	while(1)
	{
	  printf("vshell>");
	  fflush(stdin);
	  gets(com);
	  len = strlen(com);

		if(!strcmp(com, "exit"))	// if exit
		{
			delete_all(&list);	// empty the list
			return 0;
		}

		i = 0;
		while(i < len)
		{
			j = 0;
			

			while((com[i] != ' ') && (com[i] != '\0'))
			{
				buffer.s[j] = com[i];		
				i++;
				j++;
			}
		
			buffer.s[j] = '\0';
			

			insertlast(&list, buffer);
			i++;
		}
		
		pid = fork();

		if( pid == 0 ) // child
	        {
		  printf("\nforked\n");
		  f = list;
		  o = list->next;
		  s = o->next;
		  if(strcmp(o->el.s, "<") == 0)
		  {
		    close(0);
		    dup2( open ( s->el.s,O_WRONLY) , 0 ) ;
		  }
		  else if(strcmp(o->el.s, ">") == 0)
		  {
		    printf("\n1\n");
		    //		    close(4);
		    dup2(open(s->el.s, O_WRONLY), stdin);
		    printf("\n2\n");
		    execve(f->el.s, argv, NULL);
		  }
		  printf("**3**");
		  exit(0);


		}
		else     // parent
		{
		  wait(&status);
		  if(status != 0)
		    printf("Error return code = %d\n", status);
		}


		delete_all(&list);	// empty the list
	}

	delete_all(&list);	// empty the list
	return 0;
}

thanx ...