#include <stdio.h>
#include <conio.h>
#include <ctype.h>
 
 
void main(void)
{
 
 /* Declare variables*/
 
	char  text[70], *text_ptr;
	int   i;
 
	text_ptr = text;
 
 /* Prompt user for line of text*/
 
	printf ("\nEnter a line of text (up to 69 characters):\n");
	gets(text);
 
 
 /* Convert and output the text in uppercase characters.*/
 
	printf ("\nThe line of text in uppercase is:\n");
 
	i = 0;
		while ( text[i] != '\0')  
		putchar( toupper[*text_ptr]++]) );
 
 /*Convert and output the text in lowercase characters. */
 
	printf ("\n\nThe line of text in lowercase is:\n");
 
	i = 0;
		while ( text[*text_ptr] != '\0')  
		putchar( tolower(text[(*text_ptr)++]) );
 
	getch();
 
 
} // end main

#include <stdio.h>
int main ( ) {
  char test[] = "this is a test\n";
  char *p;
  int i;
  for ( i = 0 ; test[i] != '\0'; i++ ) putchar(test[i]);
  for ( p = test ; *p != '\0'; p++ ) putchar(*p);
  return 0;
}