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─────Run-Time Library───────────────────────────────────────────────────────
 
/* CASE.C illustrates case conversion and other conversions.
 * Functions illustrated include:
 *      _strupr          toupper         _toupper
 *      _strlwr          tolower         _tolower
 *      _strrev          __toascii
 */
 
#include <string.h>
#include <stdio.h>
#include <ctype.h>
 
char mstring[] = "Dog Saw Dad Live On";
char *ustring, *tstring, *estring;
char *p;
 
void main()
{
    printf( "Original:\t%s\n", mstring );
 
    /* Uppercase and lowercase */
    ustring = _strupr( _strdup( mstring ) );
    printf( "Uppercase:\t%s\n", ustring );
 
    printf( "Lowercase:\t%s\n", _strlwr( ustring ) );
 
    /* Reverse case of each character. */
    tstring = _strdup( mstring );
    for( p = tstring; *p; p++ )
    {
        if( isupper( *p ) )
            *p = tolower( *p );
        else
            *p = toupper( *p );
 
        /* This alternate code (commented out) shows how to use _tolower
         * and _toupper for the same purpose.
        if( isupper( *p ) )
            *p = _tolower( *p );
        else if( islower( *p ) )
            *p = _toupper( *p );
         */
    }
    printf( "Toggle case:\t%s\n", tstring );
 
    /* Encode and decode string. The decoding technique will convert
     * strings with some high bits set (produced by some word processors).
     */
    estring = _strdup( mstring );
    for( p = estring; *p; p++ )
        *p = *p | 0x80;
    printf( "Encoded:\t%s\n", estring );
 
    for( p = estring; *p; p++ )
        *p = __toascii( *p );
    printf( "Decoded:\t%s\n", estring );
 
    printf( "Reversed:\t%s\n", _strrev( ustring ) );
}
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