#include <stdio.h>
#include <ctype.h>

char chars[] = {
    'A',
    0x80,
    '_',
    '9',
    '+'
};

#define SIZE sizeof( chars ) / sizeof( char )

void main()
{
    int   i;

    for( i = 0; i < SIZE; i++ ) {
        printf( "Char %c is %sa C symbol character\n",
                chars[i],
                ( __iscsym( chars[i] ) ) ? "" : "not " );
    }
}