isblank()

Arguments:

c

The character you want to test. This must be representable as an unsigned char or be EOF; the behavior for other values is undefined.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The isblank() function tests the given character to see if it is a blank character. In the C locale, the set of blank characters consists of the space (' ') and the horizontal tab ('\t'). The isspace() function tests for a wider set of characters.

Returns:

Nonzero if c is a blank character; otherwise, zero.

Examples:

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

char the_chars[] = { 'A', 0x09, ' ', 0x7d, '\n' };

#define SIZE sizeof( the_chars ) / sizeof( char )

int main( void )
{
    int i;
    
    for( i = 0; i < SIZE; i++ ) {
        if( isblank( the_chars[i] ) ) {
           printf( "Char %c is a blank character\n",
                   the_chars[i] );
        } else {
           printf( "Char %c is not a blank character\n",
                   the_chars[i] );
        }
    }
        
    return EXIT_SUCCESS;
}

This program produces the output:

Char A is not a blank character
Char     is a blank character
Char   is a blank character
Char } is not a blank character
Char
 is not a blank character

Classification:

ANSI, POSIX 1003.1