K&R2 , section 5.4

PURPOSE:  see comments.
OUTPUT:   negative integer as output even for equal strings


/* A string comparison function from K&R2 
 * example code from section 5.4,page 106
 *
 * returns +ve number , if 1st string is greater than 2nd 
 * return -ve number, if 2nd string is greater than 1st
 * returns 0, if both are equal
 *
 */

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

enum MAXSIZE { ARR_SIZE = 1000 };


int my_strcmp( char*, char* );

int main( )
{
  char s1[ARR_SIZE], s2[ARR_SIZE];

  strcpy( s1, "s" );
  strcpy( s2, "s" );

  printf( "%s\t%s\t --> %d\n", s1, s2, my_strcmp( s1, s2 ));


  return EXIT_SUCCESS;
}



int my_strcmp( char* s1, char* s2 )
{
  for( ; *s1 == *s2; s1++, s2++ )
    {
      if( s1 == '\0' )
	{
	  return 0;
	}
    }
  
  return *s1 - *s2;
}

/*

  if( *s1 > *s2 )
    {
      return 1;
    }
  else if( *s1 < *s2 )
    {
      return -1;
    }
  else
    {
      return 0;
    }
*/


==================== OUTPUT ======================
Welcome to the Emacs shell

/home/arnuld/programs/C $ gcc -ansi -pedantic -Wall -Wextra section_5-5.c 
/home/arnuld/programs/C $ ./a.out 
s	s	 --> -151
/home/arnuld/programs/C $ ./a.out 
s	s	 --> -66
/home/arnuld/programs/C $ ./a.out 
s	s	 --> -122
/home/arnuld/programs/C $ ./a.out 
s	s	 --> -193
/home/arnuld/programs/C $ 




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