NAME
isblank, isblank_l
— blank-space single-byte
character test
SYNOPSIS
#include
<ctype.h>
int
isblank(int
c);
int
isblank_l(int
c, locale_t
locale);
DESCRIPTION
The
isblank()
and
isblank_l()
functions test for blank-space characters. In the C locale, the complete
list of blank-space characters is:
- ‘ ’
- Space character.
\t- Horizontal tab.
OpenBSD always uses the C locale for these functions, ignoring the global locale, the thread-specific locale, and the locale argument.
RETURN VALUES
These functions return zero if the character tests false or non-zero if the character tests true.
ENVIRONMENT
On systems supporting non-ASCII single-byte character encodings,
these functions may return non-zero for additional characters, and the
results of isblank() may depend on the
LC_CTYPE
locale(1).
SEE ALSO
isalnum(3), isalpha(3), isascii(3), iscntrl(3), isdigit(3), isgraph(3), islower(3), isprint(3), ispunct(3), isspace(3), isupper(3), iswblank(3), isxdigit(3), stdio(3), toascii(3), tolower(3), toupper(3), ascii(7)
STANDARDS
The isblank() function conforms to
ISO/IEC 9899:1999 (“ISO C99”),
and isblank_l() to IEEE Std
1003.1-2008 (“POSIX.1”).
HISTORY
The isblank() function has been available
since 4.4BSD, and
isblank_l() since OpenBSD
6.2.
CAVEATS
The argument c must be
EOF or representable as an unsigned
char; otherwise, the result is undefined.