olibc/src/ctype.c

#include <ctype.h>

int isdigit(int c) {
  return (unsigned)c-'0' < 10;
}

int isxdigit(int c) {
  return isdigit(c) || ((unsigned)c|32)-'a' < 6;
}

int isblank(int c) {
  return (c == ' ' || c == '\t');
}

int isspace(int c) {
  return (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v');
}

int islower(int c) {
  return (unsigned)c-'a' < 26;
}

int isupper(int c) {
  return (unsigned)c-'A' < 26;
}