/*  States.c  (c) Kari Laitinen

    http://www.naturalprogramming.com/

    2013-11-24 File created.
    2013-11-24 Last modification.

    This program demonstrates the use of the string functions
    in string.h.
*/

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

int main()
{
   char states_in_usa[ 120 ] ;

   char westmost_state[]  =  "Hawaii" ;
   char prairie_state[]   =  "Illinois" ;

   strcpy( states_in_usa, westmost_state ) ;
   strcat( states_in_usa, "  " ) ;
   strcat( states_in_usa, prairie_state ) ;

   printf( "\n   %s", states_in_usa ) ;

   char golden_state[]   =  "California" ;

   /*  We'll first move bytes in memory so that there will be
       enough space for the text "  California". */

   memmove( &states_in_usa[ 6 ] + strlen( golden_state ) + 2,
            &states_in_usa[ 6 ],
            strlen( &states_in_usa[ 6 ] ) ) ;

   /*  Next, we'll copy two strings to the 'hole' in the string
       pointed by states_in_usa. */

   strncpy( &states_in_usa[ 6 ] + 2, golden_state, strlen( golden_state ) ) ;
   strncpy( &states_in_usa[ 6 ], "  ", 2 ) ;

   printf( "\n   %s", states_in_usa ) ;

   char eastmost_state[]  =  "Maine" ;

   strcat( states_in_usa, "  Virginia  " ) ;
   strcat( states_in_usa, eastmost_state ) ;

   printf( "\n   %s", states_in_usa ) ;

   char* pointer_to_last_state  =  strrchr( states_in_usa, ' ' ) ;

   /*  By writing a zero, we can erase the last state in the list. */

   *pointer_to_last_state = 0 ;

   strcat( states_in_usa, " Massachusetts" ) ;

   printf( "\n   %s", states_in_usa ) ;

   strncpy( strstr( states_in_usa, "Illinois" ), 
            "Michigan", 8 ) ;

   printf( "\n   %s\n", states_in_usa ) ;
}

/*  The output of this program is the following.

   Hawaii  Illinois
   Hawaii  California  Illinois
   Hawaii  California  Illinois  Virginia  Maine
   Hawaii  California  Illinois  Virginia  Massachusetts
   Hawaii  California  Michigan  Virginia  Massachusetts

*/