isalpha(), isalpha_l()

tests if character is alphabetic 

Function


SYNOPSIS

#include <ctype.h>

int isalpha(int c);

int isalpha_l(int c, locale_t locale);


DESCRIPTION

The isalpha() function tests for any character for which isupper() or islower() is true, or any character that is one of an implementation-defined set of characters for which none of iscntrl(), isdigit(), ispunct(), or isspace() is true. In the C locale, isalpha() returns true only for the characters for which isupper() or islower() is true.

The behavior of the isalpha() function is affected by the current locale. To modify the behavior, change the LC_CTYPE category in setlocale(), that is, setlocale(LC_CTYPE, newlocale). In the C locale or in a locale where character type information is not defined, characters are classified according to the rules of the U.S. ASCII 7-bit coded character set.

isalpha_l() behaves in the same way as isalpha() without the _l suffix, but uses the specified locale rather than the global or per-thread locale. A locale_t is returned by newlocale().


PARAMETERS

c 

Is an integer whose value is representable as an unsigned char or the value of the macro EOF.

locale 

Is a locale_t perhaps returned by newlocale() or LC_GLOBAL_LOCALE or 0 for the current thread locale set with uselocale().


RETURN VALUES

The isalpha() and isalpha_l() functions return non-zero for true and zero for false. If the parameter is not in the domain of the function or the locale is invalid, the return result is undefined.


CONFORMANCE

isalpha() conforms to ANSI/ISO 9899-1990.


MULTITHREAD SAFETY LEVEL

MT-Safe, with exceptions.

The function isalpha() is MT-Safe as long as no thread calls setlocale() while this function is executing.

The function isalpha_l() is MT-Safe as long as no thread calls freelocale() on locale while this function is executing.


PORTING ISSUES

None.


AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition


SEE ALSO

Functions:
isalnum(), isalnum_l(), isascii(), isascii_l(), iscntrl(), iscntrl_l(), isdigit(), isdigit_l(), isgraph(), isgraph_l(), islower(), islower_l(), isprint(), isprint_l(), ispunct(), ispunct_l(), isspace(), isspace_l(), isupper(), isupper_l(), isxdigit(), isxdigit_l(), setlocale(), xlocale()


PTC MKS Toolkit 10.1 Documentation Build 15.