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


int l4_read_string(char *s, int max) {
  int retval;
  //read from l3
  retval=l3_read(s,max);
  if(retval!=-1) {
    //add a null
    s[retval]=0;
    return(retval+1);
  } else {
    //l3 failed
    printf("Failure\n");
    return(-1);
  }
} 

int l4_read_estring(char *s, int max) {
  int retval;
  int a;
  char *buff;
  //allocate another buffer
  if(!(buff=(char *)malloc(max))) {
    printf("Malloc error\n");
    return -1;
  }
  //read from layer 3
  retval=l3_read(buff,max);
  if(retval!=-1) {
    for(a=0;a<retval;a++) {
      //"encryption"
      s[a]=buff[a]^0x55;
    }
    s[retval]=0;
    //malloc memory and then free it
    free(buff);
    return(retval+1);
  } else {
    //failure
    free(buff);
    return(-1);
  }
}


int l4_write_string(char *s) {
  //simply calls l4 write
  return(l3_write(s,strlen(s)));
}

int l4_write_estring(char *s){
  char *buff;
  int a;
  if(! (buff=(char *)malloc(strlen(s)))) {
    printf("MEMORY ERROR\n");
    return -1;
  }
  //encrypt each byte
  for(a=0;a<strlen(s);a++) {
    //encryption
    buff[a]=s[a]^0x55;
  }
  a=l3_write(buff,strlen(s));
  free(buff);
  return a;
}