| ISBLANK(3) | Library Functions Manual | ISBLANK(3) | 
NAME
 isblank — blank-space character test
LIBRARY
 Standard C Library (libc, -lc)
SYNOPSIS
 #include <ctype.h>
int
isblank(int c);
 
DESCRIPTION
 The 
isblank() function tests for the standard blank-space characters. The standard blank-space characters are the following:
- 
‘ '
- 
Space character.
- 
\t
- 
Horizontal tab.
In the ``C'' locale, isblank() returns true only for the standard blank-space characters.
 
RETURN VALUES
 The isblank() function returns zero if the character tests false and returns non-zero if the character tests true.
SEE ALSO
 ctype(3), 
isalnum(3), 
isalpha(3), 
isascii(3), 
iscntrl(3), 
isdigit(3), 
isgraph(3), 
islower(3), 
isprint(3), 
ispunct(3), 
isspace(3), 
isupper(3), 
isxdigit(3), 
stdio(3), 
toascii(3), 
tolower(3), 
toupper(3), 
ascii(7) 
CAVEATS
 The argument to 
isblank() must be 
EOF or representable as an 
unsigned char; otherwise, the behavior is undefined. See the 
CAVEATS section of 
ctype(3) for more details.