#include<stdio.h>
    #include<stdlib.h>
    #include<fcntl.h>
    #include<unistd.h>
    #include<string.h>

    int main(int argc, char* argv[]) {
    	
    	int fird,ent,ents;
    	short int i;
    	off_t l;
    	char tst[256];
    	size_t n=1,m=1;
    	memset(tst,0,256);

    		if(argc!=4){
    			printf("erreur : %s <file_name> <32-bit int in Hex> <Offset in Hex>\n",argv[0]);
    			exit(-1);
    		}

    	fird=open(argv[1],O_CREAT|O_WRONLY,0600);
    		if(fird==-1){
    			perror("On ne peut pas ouvrir cela en O_RDONLY");
    			exit(1);
    		}

    	ent = strtol(argv[3],NULL,16);

    	l=lseek(fird,ent*4,SEEK_SET);
    	printf("%ld\n",l);
    	
    	if(l==-1){
    			perror("erreur dans lseek");
    			exit(2);
    		}

    	
    	ents = strtol(argv[2],NULL,16);

    	write(fird,&ents,4);

    	close(fird);

    	return EXIT_SUCCESS;
    }