Question

I have 2 language codes coming in the stream. I’m storing this in a 3 byte char array(unsigned char a[3]). I wanted to compare it with another value stored in a pointer(unsigned char *c).The array a[3] is stored inside a structure(struct s[2]) to get the multiple datas – Is this correct as i’m little confused as array – const pointer cannot be made to point to another location as it is already pointing to a location. But including the array inside a structure and making the zeorth element of the structures array to point to one location and the 1 st element of the structures array is possible. Is the understanding i have is correct.

I wanted to store the 2 array values.So I have declared a structure inside which i have declared the 3 byte char array.Is this way of doing is correct. Is there alternate way to do it.

EDITED:

   #include<stdio.h>
int main(){
 int i,flag=0,count=0;
 struct n{
  unsigned char b[3];
 };
 unsigned char *d=NULL; 
 struct s{
  unsigned char *a;
 };
 struct s m[2];
 struct n w[2];
// memcpy(w[0].b,"eng",sizeof("eng"));
// memcpy(w[1].b,"fre",sizeof("fre"));
strcpy(w[0].b,"eng");
strcpy(w[1].b,"fre");

 d = w[1].b; // current lang
 m[0].a = w[0].b; // storing the 2 lang in a pointer inside a structure
 m[1].a = w[1].b;
 i=0;
 printf("\nm[0].a:%s\n",m[0].a);
 printf("\nm[1].a:%s\n",m[1].a);
printf("\nw[0].b:%s\n",w[0].b);
 printf("\nw[1].b:%s\n",w[1].b);
 while((m[i].a) && d){ // And comparing
  if(m[i].a++ != d++){ 
   flag =1; //if strings are unequal break;
   break;
  }
 i++;
 }
  if(flag){
   printf("Not equal\n");
  }
  else{
   printf("\nEqual\n");
   flag =0;
  }
 return 0;
}

o/p:

m[0].a:engfre

m[1].a:fre

w[0].b:engfre

w[1].b:fre
Not equal

But there s an mistake it shows un equal . Is this way of storing the arrays in a pointer inside a strucutre is correct method. or is there any other way to do this.

EDIT:

I wanted to compare the 2 strings. The 2 strings are equal but i’m getting it as unequal.
Is the pointer a need to be stored in a structure to store the 2 arrays or is there another way of dong this.

Answer 1

#include <stdio.h>
#include <string.h>
int main(){
  int i,flag=0,count=0;
  struct n{
    unsigned char b[4];
  };
  struct s{
    unsigned char *a;
  };
  unsigned char *d=NULL; 
  struct s m[2];
  struct n w[2];
  strcpy(w[0].b,"eng");
  strcpy(w[1].b,"fre");
  d = w[1].b; // current lang
  m[0].a = w[0].b; // storing the 2 lang in a pointer inside a structure
  m[1].a = w[1].b;
  for (i =0; i <= 1; i++) {
    printf("\nm[%d].a: %s d: %s\n", i, m[i].a, d);
    if (strcmp(m[i].a, d) != 0) {
      printf("Not equal\n");
    }
    else{
      printf("\nEqual\n");
    }
  }
  return 0;
}