1CTYPE(3)                   Library Functions Manual                   CTYPE(3)
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NAME

6       isalpha,   isupper,   islower,  isdigit,  isxdigit,  isalnum,  isspace,
7       ispunct, isprint, isgraph, iscntrl, isascii, toupper, tolower,  toascii
8       - character classification macros
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SYNOPSIS

11       #include <ctype.h>
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13       isalpha(c)
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15       . . .
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DESCRIPTION

18       These macros classify ASCII-coded integer values by table lookup.  Each
19       is a predicate returning nonzero for true, zero for false.  Isascii and
20       toascii  are  defined  on all integer values; the rest are defined only
21       where isascii is true and  on  the  single  non-ASCII  value  EOF  (see
22       stdio(3S)).
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24       isalpha        c is a letter
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26       isupper        c is an upper case letter
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28       islower        c is a lower case letter
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30       isdigit        c is a digit
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32       isxdigit       c is a hex digit
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34       isalnum        c is an alphanumeric character
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36       isspace        c  is  a  space, tab, carriage return, newline, vertical
37                      tab, or formfeed
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39       ispunct        c  is  a  punctuation  character  (neither  control  nor
40                      alphanumeric)
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42       isprint        c  is  a printing character, code 040(8) (space) through
43                      0176 (tilde)
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45       isgraph        c is a printing character,  similar  to  isprint  except
46                      false for space.
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48       iscntrl        c is a delete character (0177) or ordinary control char‐
49                      acter (less than 040).
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51       isascii        c is an ASCII character, code less than 0200
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53       tolower        c is converted to lower case.  Return value is undefined
54                      if not isupper(c).
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56       toupper        c is converted to upper case.  Return value is undefined
57                      if not islower(c).
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59       toascii        c is converted to be a valid ascii character.
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SEE ALSO

62       ascii(7)
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667th Edition                      May 12, 1986                         CTYPE(3)
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