isdigit(), isdigit_l()

tests if character is a digit 

Function


SYNOPSIS

#include <ctype.h>

int isdigit(int c);

int isdigit_l(int c, locale_t locale);


DESCRIPTION

The isdigit() function tests for any decimal-digit character.

The behavior of the isdigit() 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.

The behavior of the isdigit_l() function is affected by the specified locale. To modify the behavior, change the LC_CTYPE category in newlocale() that is, newlocale(LC_CTYPE, new_locale). 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.


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 isdigit() and isdigit_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

The isdigit() function conforms to ANSI/ISO 9899-1990.


MULTITHREAD SAFETY LEVEL

MT-Safe, with exceptions.

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

The function isdigit_l() is MT-Safe as long as no thread calls freelocale() on the 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(), isalpha(), isalpha_l(), isascii(), isascii_l(), iscntrl(), iscntrl_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.