glenda.party
term% ls -F
term% cat index.txt
CTYPE(3)                   Library Functions Manual                   CTYPE(3)



NAME
       isalpha, isupper, islower, isdigit, isalnum, isspace, ispunct, isprint,
       iscntrl, isascii - character classification

SYNOPSIS
       #include <ctype.h>

       isalpha(c)

       . . .

DESCRIPTION
       These macros classify ASCII-coded integer values by table lookup.  Each
       is  a predicate returning nonzero for true, zero for false.  Isascii is
       defined on all integer values; the rest are defined only where  isascii
       is true and on the single non-ASCII value EOF (see stdio(3)).

       isalpha        c is a letter

       isupper        c is an upper case letter

       islower        c is a lower case letter

       isdigit        c is a digit

       isalnum        c is an alphanumeric character

       isspace        c is a space, tab, carriage return, newline, or formfeed

       ispunct        c  is  a  punctuation character (neither control nor al‐
                      phanumeric)

       isprint        c is a printing character, code 040(8)  (space)  through
                      0176 (tilde)

       iscntrl        c is a delete character (0177) or ordinary control char‐
                      acter (less than 040).

       isascii        c is an ASCII character, code less than 0200

SEE ALSO
       ascii(7)



                                                                      CTYPE(3)