1.\" $OpenBSD: isblank.3,v 1.11 2013/07/06 17:31:20 jmc Exp $ 2.\" 3.\" Copyright (c) 1991 The Regents of the University of California. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the American National Standards Committee X3, on Information 8.\" Processing Systems. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.Dd $Mdocdate: July 6 2013 $ 35.Dt ISBLANK 3 36.Os 37.Sh NAME 38.Nm isblank 39.Nd blank-space character test 40.Sh SYNOPSIS 41.In ctype.h 42.Ft int 43.Fn isblank "int c" 44.Sh DESCRIPTION 45The 46.Fn isblank 47function tests for the standard blank-space characters. 48The standard blank-space characters are the following: 49.Pp 50.Bl -tag -width xxxxx -offset indent -compact 51.It Sq \0 52Space character. 53.It Li \et 54Horizontal tab. 55.El 56.Pp 57In the C locale, 58.Fn isblank 59returns true only for the standard blank-space characters. 60.Sh RETURN VALUES 61The 62.Fn isblank 63function returns zero if the character tests false or 64non-zero if the character tests true. 65.Sh SEE ALSO 66.Xr isalnum 3 , 67.Xr isalpha 3 , 68.Xr isascii 3 , 69.Xr iscntrl 3 , 70.Xr isdigit 3 , 71.Xr isgraph 3 , 72.Xr islower 3 , 73.Xr isprint 3 , 74.Xr ispunct 3 , 75.Xr isspace 3 , 76.Xr isupper 3 , 77.Xr isxdigit 3 , 78.Xr stdio 3 , 79.Xr toascii 3 , 80.Xr tolower 3 , 81.Xr toupper 3 , 82.Xr ascii 7 83.Sh CAVEATS 84The argument to 85.Fn isblank 86must be 87.Dv EOF 88or representable as an 89.Li unsigned char ; 90otherwise, the result is undefined. 91