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ISALPHA !!!ISALPHA NAME SYNOPSIS DESCRIPTION RETURN VALUE CONFORMING TO NOTE SEE ALSO ---- !!NAME isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph, islower, isprint, ispunct, isspace, isupper, isxdigit - character classification routines !!SYNOPSIS __#include __ ''c''__); int isalpha (int__ ''c''__); int isascii (int__ ''c''__); int isblank (int__ ''c''__); int iscntrl (int__ ''c''__); int isdigit (int__ ''c''__); int isgraph (int__ ''c''__); int islower (int__ ''c''__); int isprint (int__ ''c''__); int ispunct (int__ ''c''__); int isspace (int__ ''c''__); int isupper (int__ ''c''__); int isxdigit (int__ ''c''__); __ !!DESCRIPTION These functions check whether ''c'', which must have the value of an __unsigned char__ or __EOF__, falls into a certain character class according to the current locale. __isalnum()__ checks for an alphanumeric character; it is equivalent to __(isalpha(__''c''__) || isdigit(__''c''__))__. __isalpha()__ checks for an alphabetic character; in the standard ____ locale, it is equivalent to __(isupper(__''c''__) || islower(__''c''__))__. In some locales, there may be additional characters for which __isalpha()__ is true--letters which are neither upper case nor lower case. __isascii()__ checks whether ''c'' is a 7-bit ''unsigned char'' value that fits into the ASCII character set. This function is a BSD extension and is also an SVID extension. __isblank()__ checks for a blank character; that is, a space or a tab. This function is a GNU extension. __iscntrl()__ checks for a control character. __isdigit()__ checks for a digit (0 through 9). __isgraph()__ checks for any printable character except space. __islower()__ checks for a lower-case character. __isprint()__ checks for any printable character including space. __ispunct()__ checks for any printable character which is not a space or an alphanumeric character. __isspace()__ checks for white-space characters. In the ____ and ____ locales, these are: space, form-feed (__'f'__), newline (__'n'__), carriage return (__'r'__), horizontal tab (__'t'__), and vertical tab (__'v'__). __isupper()__ checks for an uppercase letter. __isxdigit()__ checks for a hexadecimal digits, i.e. one of __0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F__. !!RETURN VALUE The values returned are nonzero if the character ''c'' falls into the tested class, and a zero value if not. !!CONFORMING TO ANSI - C, BSD 4.3. __isascii()__ is a BSD extension and is also an SVID extension. __isblank()__ is a GNU extension. !!NOTE The details of what characters belong into which class depend on the current locale. For example, __isupper()__ will not recognize an A - umlaut as an uppercase letter in the default __C__ locale. !!SEE ALSO tolower(3), toupper(3), setlocale(3), ascii(7), locale(7) ----
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