test for any hexadecimal digit
#include <ctype.h> int isxdigit( int c );
The isxdigit() function tests for any hexadecimal-digit character. These characters are the digits ('0' through '9') and the letters ('a' through 'f') and ('A' through 'F').
The isxdigit() function returns a non-zero value when the argument is a hexadecimal digit; otherwise, it returns zero.
isalnum(), isalpha(), iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(), isspace(), isupper(), tolower(), toupper()
#include <stdio.h>
#include <ctype.h>
char chars[] = {'A', '5', '$'};
#define SIZE sizeof( chars ) / sizeof( char )
void main()
{
int i;
for( i = 0; i < SIZE; i++ ) {
printf( "Char %c is %sa hexadecimal digit"
" character\n", chars[i],
( isxdigit( chars[i] ) ) ? "" : "not " );
}
}
produces the output
Char A is a hexadecimal digit character Char 5 is a hexadecimal digit character Char $ is not a hexadecimal digit character
ANSI
All (except DOS/PM)