#include <stdint.h>  //  allows uint16_t, int64_t
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>

char   progid[80] = "square_it.c by John Copeland  4/1/2011, 3/31/14" ; 

void pr_buf( char* p, int m)
{
	int i ;
	printf("The memory address of buff is %x\n", (uint32_t) p );
	for( i=0 ; i< m ; i++ )
	{
		if(( p[i] > 31 ) && ( p[i] < 127 ))  // 32 is space, 127 is delete, 
			printf("%c,", p[i] ) ;
		else
			printf("%2x,", (unsigned char) p[i] ) ;  // print as 2-space hex, -128 to 31, and 127
	}
	printf("\n") ;
	return ;
}

int do_square( int x)   //  "x" here is a local variable, stored in a different
{                       //   location (on the stack) from the "x" in main
	x = x * x ;
	return( x ) ;
}

int main(int argc, char * argv[ ])
{
  int     x, y ;    // modern: replace "int" with "int32_t"
  char    buf[5] ; 
  printf("\n%s\n", progid ) ;
  
	while(1)
	{
		printf("\n Type number (q = quit) : ") ;
		gets( buf ) ;        
		if( buf[0] == 'q' ) break ;
		x = atoi( buf ) ;
		printf(" ----  x = %i buf = %s\n", x, buf ) ;
		pr_buf( buf, 50 ) ;
		y = do_square( x ) ;
		printf("--The square of %i is %i\n", x, y );
	}
	return( 0 ) ;
}
/* =============  EXAMPLE OUTPUT  ==============
 square_it.c by John Copeland  4/1/2011, 3/31/14
 
 Type number (q = quit) : 3       
 ----  x = 3 buf = 3
 The memory address of buff is 5fbff910
 3, 0,bf,_,ff,, 0, 0,R,10,c0,_, 3, 0, 0, 0,0,f9,bf,_,ff,, 0, 0,fc, c, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0,18,fa,
 --The square of 3 is 9
 
 Type number (q = quit) : 3 This_is_overflowing_the_buffer.
 ----  x = 3 buf = 3 This_is_ov
 3, ,T,h,i,s,_,i,s,_,o,v, 3, 0, 0, 0,o,w,i,n,g,_,t,h,e,_,b,u,f,f,e,r,., 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0,18,fa,
 --The square of 3 is 9
 
 Type number (q = quit) : q   
 Segmentation fault              // we overwrote the return address of main()
 ========================== */