1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)isblank.3 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd July 17, 2005 32.Dt ISBLANK 3 33.Os 34.Sh NAME 35.Nm isblank 36.Nd space or tab character test 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In ctype.h 41.Ft int 42.Fn isblank "int c" 43.Sh DESCRIPTION 44The 45.Fn isblank 46function tests for a space or tab character. 47For any locale, this includes the following standard characters: 48.Pp 49.Bl -column \&`\et''___ \&``\et''___ 50.It "\&``\et''\t`` ''" 51.El 52.Pp 53In the "C" locale 54.Fn isblank 55successful test is limited to this characters only. 56The value of the argument must be representable as an 57.Vt "unsigned char" 58or the value of 59.Dv EOF . 60.Sh RETURN VALUES 61The 62.Fn isblank 63function returns zero if the character tests false and 64returns non-zero if the character tests true. 65.Sh COMPATIBILITY 66The 67.Bx 4.4 68extension of accepting arguments outside of the range of the 69.Vt "unsigned char" 70type in locales with large character sets is considered obsolete 71and may not be supported in future releases. 72The 73.Fn iswblank 74function should be used instead. 75.Sh SEE ALSO 76.Xr ctype 3 , 77.Xr iswblank 3 , 78.Xr ascii 7 79.Sh STANDARDS 80The 81.Fn isblank 82function 83conforms to 84.St -isoC-99 . 85