ctype.c

   1 #include <ctype.h>
   2
   3 int isascii(int c)
   4 {
   5         return (unsigned) c < 128u;
   6 }
   7
   8 int isblank(int c)
   9 {
  10         return c == ' ' || c == '\t';
  11 }
  12
  13 int isalpha(int c)
  14 {
  15         return (unsigned) ((c | 0x20) - 'a') < 26u;
  16 }
  17
  18 int isdigit(int c)
  19 {
  20         return (unsigned) (c - '0') < 10u;
  21 }
  22
  23 int isalnum(int c)
  24 {
  25         return (unsigned) ((c | 0x20) - 'a') < 26u ||
  26                 (unsigned) (c - '0') < 10u;
  27 }
  28
  29 int isspace(int c)
  30 {
  31         return (unsigned) (c - 9) < 5u || c == ' ';
  32 }
  33
  34 int isupper(int c)
  35 {
  36         return (unsigned) (c - 'A') < 26u;
  37 }
  38
  39 int islower(int c)
  40 {
  41         return (unsigned) (c - 'a') < 26u;
  42 }
  43
  44 int tolower(int c)
  45 {
  46         return (unsigned) (c - 'A') < 26u ? c + ('a' - 'A') : c;
  47 }
  48
  49 int toupper(int c)
  50 {
  51         return (unsigned) (c - 'a') < 26u ? c + ('A' - 'a') : c;
  52 }
  53
  54 int isprint(int c)
  55 {
  56         return (c & 0x7f) >= 32 && (c & 0x7f) < 127;
  57 }