NAME
isblank isblank_l
— test for a blank character
SYNOPSIS
#include
<ctype.h>
int isblank(int c); [CX] int isblank_l(int c, locale_t locale);
DESCRIPTION
For isblank (): [CX] The
functionality described on this reference page is aligned with the ISO C
standard. Any conflict between the requirements described here and the ISO C
standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C
standard.
The isblank ()
[CX] and isblank_l () functions shall
test whether c is a character of class
blank in the
current locale of the process, [CX] or in the locale
represented by
locale,
respectively; see XBD V1_chap07(7) .
The c argument is a type int, the value of which the application shall ensure is a character representable as an unsigned char or equal to the value of the macro EOF. If the argument has any other value, the behavior is undefined.
RETURN VALUE
The isblank () [CX] and
isblank_l () functions shall return non-zero if
c is a <blank>; otherwise, they shall return 0.
ERRORS
The isblank_l () function may fail if:
- [EINVAL]
- [CX] locale is not a valid locale object handle.
EXAMPLES
None.
APPLICATION USAGE
To ensure applications portability, especially across natural languages, only these functions and the functions in the reference pages listed in the SEE ALSO section should be used for character classification.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
isalnum(3) , isalpha(3) , iscntrl(3) , isdigit(3) , isgraph(3) , islower(3) , isprint(3) , ispunct(3) , isspace(3) , isupper(3) , isxdigit(3) , setlocale(3) , uselocale(3)
XBD V1_chap07(7) , <ctype.h> , <locale.h>
CHANGE HISTORY
First released in Issue 6. Derived from the ISO/IEC 9899:1999 (“ISO C99”) standard.
Issue 7
The isblank_l () function is added from The Open Group Technical Standard, 2006, Extended API Set Part 4.