ctype.h
#ifndef BOOT_CTYPE_H
#define BOOT_CTYPE_H
static inline int isdigit(int ch)
{
return (ch >= '0') && (ch <= '9');
}
static inline int isxdigit(int ch)
{
if (isdigit(ch))
return true;
if ((ch >= 'a') && (ch <= 'f'))
return true;
return (ch >= 'A') && (ch <= 'F');
}
#endif