iscntrl(3STDC)

NAME | SYNOPSIS | API RESTRICTIONS | DESCRIPTION | DIAGNOSTICS | ATTRIBUTES

NAME

ctype, isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, tolower, toupper- classify characters

SYNOPSIS

All functions described in this page have the same syntax.

#include <ctype.h>

int isalpha(int c);

API RESTRICTIONS

The function or functions documented here may not be used safely in all application contexts with all APIs provided in the ChorusOS 5.0 product.

See API(5FEA) for details.

DESCRIPTION

These macros classify character-coded integer values by looking them up in a table. Each is a predicate returning nonzero for true, or zero for false.

isalpha()

c is a letter.

isupper()

c is an upper-case letter.

islower()

c is a lower-case letter.

isdigit()

c is a digit [0-9].

isxdigit()

c is a hexadecimal digit [0-9], [A-F] or [a-f].

isalnum()

c is an alphanumeric (letter or digit).

isspace()

c is a space, tab, carriage return, new-line, vertical tab, or form-feed.

ispunct()

c is a punctuation character (neither control nor alphanumeric).

isprint()

c is a printing character, code 040 (space) to 0176 (tilde).

isgraph()

c is a printing character, like isprint except for space.

iscntrl()

c is a delete character (0177) or an ordinary control character (less than 040).

The conversion functions and macros translate a character from lowercase (uppercase) to uppercase (lowercase).

tolower()

If c is a character for which isupper() is true and there is a corresponding lowercase character, tolower() returns the corresponding lowercase character. Otherwise, the character is returned unchanged.

toupper()

If c is a character for which islower() is true and there is a corresponding uppercase character, toupper() returns the corresponding uppercase character. Otherwise, the character is returned unchanged.

DIAGNOSTICS

If the argument to any of these macros is not in the domain of the function, the result is undefined.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Evolving

NAME | SYNOPSIS | API RESTRICTIONS | DESCRIPTION | DIAGNOSTICS | ATTRIBUTES