April 17, 2008 ISBLANK 3

### NAME

isblank - blank-space character test

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```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 otherwise, the behavior is undefined. See the CAVEATS section of ctype(3) for more details.