The Open Group Base Specifications Issue 7, 2018 edition
IEEE Std 1003.1-2017 (Revision of IEEE Std 1003.1-2008)
Copyright © 2001-2018 IEEE and The Open Group
A newer edition of this document exists here

NAME

ctype.h - character types

SYNOPSIS

#include <ctype.h>

DESCRIPTION

[CX] [Option Start] Some of the functionality described on this reference page extends the ISO C standard. Applications shall define the appropriate feature test macro (see XSH The Compilation Environment ) to enable the visibility of these symbols in this header.

The <ctype.h> header shall define the locale_t type as described in <locale.h>, representing a locale object. [Option End]

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided for use with ISO C standard compilers.

int   isalnum(int);
[CX][Option Start]
int   isalnum_l(int, locale_t);
[Option End]
int   isalpha(int);
[CX][Option Start]
int   isalpha_l(int, locale_t);
[Option End]
[OB XSI][Option Start]
int   isascii(int);
[Option End]
int   isblank(int);
[CX][Option Start]
int   isblank_l(int, locale_t);
[Option End]
int   iscntrl(int);
[CX][Option Start]
int   iscntrl_l(int, locale_t);
[Option End]
int   isdigit(int);
[CX][Option Start]
int   isdigit_l(int, locale_t);
[Option End]
int   isgraph(int);
[CX][Option Start]
int   isgraph_l(int, locale_t);
[Option End]
int   islower(int);
[CX][Option Start]
int   islower_l(int, locale_t);
[Option End]
int   isprint(int);
[CX][Option Start]
int   isprint_l(int, locale_t);
[Option End]
int   ispunct(int);
[CX][Option Start]
int   ispunct_l(int, locale_t);
[Option End]
int   isspace(int);
[CX][Option Start]
int   isspace_l(int, locale_t);
[Option End]
int   isupper(int);
[CX][Option Start]
int   isupper_l(int, locale_t);
[Option End]
int   isxdigit(int);
[CX][Option Start]
int   isxdigit_l(int, locale_t);
[Option End]
[OB XSI][Option Start]
int   toascii(int);
[Option End]
int   tolower(int);
[CX][Option Start]
int   tolower_l(int, locale_t);
[Option End]
int   toupper(int);
[CX][Option Start]
int   toupper_l(int, locale_t);
[Option End]

The <ctype.h> header shall define the following as macros:

[OB XSI][Option Start]
int   _toupper(int);
int   _tolower(int);
[Option End]


The following sections are informative.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

<locale.h>

XSH The Compilation Environment, isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph, islower, isprint, ispunct, isspace, isupper, isxdigit, mblen, mbstowcs, mbtowc, setlocale, toascii, tolower, _tolower, toupper, _toupper, wcstombs, wctomb

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

Extensions beyond the ISO C standard are marked.

Issue 7

SD5-XBD-ERN-6 is applied, updating the wording regarding the function declarations for consistency.

The *_l() functions are added from The Open Group Technical Standard, 2006, Extended API Set Part 4.

End of informative text.

 

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