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

6       isalpha, isupper, islower, isdigit, isalnum, isspace, ispunct, isprint,
7       iscntrl, isascii - character classification
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SYNOPSIS

10       #include <ctype.h>
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12       isalpha(c)
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14       . . .
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DESCRIPTION

17       These macros classify ASCII-coded integer values by table lookup.  Each
18       is  a predicate returning nonzero for true, zero for false.  Isascii is
19       defined on all integer values; the rest are defined only where  isascii
20       is true and on the single non-ASCII value EOF (see stdio(3)).
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22       isalpha        c is a letter
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24       isupper        c is an upper case letter
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26       islower        c is a lower case letter
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28       isdigit        c is a digit
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30       isalnum        c is an alphanumeric character
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32       isspace        c is a space, tab, carriage return, newline, or formfeed
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34       ispunct        c  is  a  punctuation  character  (neither  control  nor
35                      alphanumeric)
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37       isprint        c is a printing character, code 040(8)  (space)  through
38                      0176 (tilde)
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40       iscntrl        c is a delete character (0177) or ordinary control char‐
41                      acter (less than 040).
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43       isascii        c is an ASCII character, code less than 0200
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SEE ALSO

46       ascii(7)
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50                                                                      CTYPE(3)