Copy to Buffers

I am writng a fucntion that Compares two strings alphabetically, case-INsensitive.

The instructions are :

* Copy the two strings to local buffers (arrays), change both string *COPIES to upper case; Compare the two strings using myStrCmp().

Code:

---

int myStrBlindCmp(unsigned char change_one[], unsigned char change_two[])
{

}

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is what i have :p

i know that to change to uppercase would look like this:

Code:

---

        // To Uppercase
        for ( x=0; string[x] != '\0'; ++x)
                if ( string[x] >= 'a' && string[x] <= 'z')
                        string[x] = string[x] - (32);

---

and myStrCmp looks like this:

Code:

---


int myStrCmp (unsigned char one[],unsigned char two[])
{
        int i=0,x=0;

        while (one[i]==two[i] && one[i] != '\0' && two[i] != '\0')
                ++i;
       
        if (one[i] == '\0' && two[i] =='\0')
                        x=0;
        else
                if (one[i] > two[i] )
                        x=1;
        else
                x= -1;
                return (x);       
}

---

but how do you copy to local buffers and put this all together???

>i know that to change to uppercase would look like this
Maybe 20 years ago. These days we do this:

Code:

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for (x = 0; string[x] != '\0'; ++x)
  string[x] = toupper((unsigned char)string[x]);

---

>but how do you copy to local buffers and put this all together???
You have to bring out the big guns:

Code:

---

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

int my_stricmp(const char *a, const char *b)
{
  int la = strlen(a) + 1;
  int lb = strlen(b) + 1;
  char *ca = malloc(la);
  char *cb = malloc(lb);
  int i;

  for (i = 0; i < la; i++)
    ca[i] = (char)toupper((unsigned char)a[i]);
  for (i = 0; i < lb; i++)
    cb[i] = (char)toupper((unsigned char)b[i]);

  i = strcmp(ca, cb);

  free(ca);
  free(cb);

  return i;
}

int main(void)
{
  char *a = "test";
  char *b = "TeSt";

  printf("%d\n", my_stricmp(a, b));

  return 0;
}

---

The olny reason i actually wrote it out was because i had to. I am not allowed to use ToUpper or ToLower... also i am not allowed to use pointers which makes it more difficult

>I am not allowed to use ToUpper or ToLower...
I don't know why teachers still assign this exercise. ASCII isn't a ubiquitous standard, so it would be better to just explain how such a conversion would be made in ASCII and then allow the students to use portable functions as they would in the real world.

>also i am not allowed to use pointers which makes it more difficult
No, it makes it impossible if you still want to copy the strings. Have you considered not making a copy in favor of handling each character in order?

Code:

---

while (toupper(a[i]) == toupper(b[i])) {
  if (a[i++] == '\0')
    return 0;
}

if (a[i] < b[i])
  return -1;
else
  return +1;

---

Since you already know how to perform the conversion, writing your own toupper for convenience is trivial.