isxdigit
Header: <ctype.h>
Checks if the given character is a hexadecimal numeric character (0123456789abcdefABCDEF) or is classified as a hexadecimal character.
# Declarations
int isxdigit( int ch );
# Parameters
ch: character to classify
# Return value
Non-zero value if the character is an hexadecimal numeric character, zero otherwise.
# Notes
isdigit and isxdigit are the only standard narrow character classification functions that are not affected by the currently installed C locale, although some implementations (e.g. Microsoft in 1252 codepage) may classify additional single-byte characters as digits.
# Example
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
int main(void)
{
for (int ndx = 0; UCHAR_MAX >= ndx; ++ndx)
if (isxdigit(ndx))
printf("%c", ndx);
printf("\n");
}