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.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)isblank.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd July 17, 2005 36.Dt ISBLANK 3 37.Os 38.Sh NAME 39.Nm isblank 40.Nd space or tab character test 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In ctype.h 45.Ft int 46.Fn isblank "int c" 47.Sh DESCRIPTION 48The 49.Fn isblank 50function tests for a space or tab character. 51For any locale, this includes the following standard characters: 52.Pp 53.Bl -column \&`\et''___ \&``\et''___ 54.It "\&``\et''\t`` ''" 55.El 56.Pp 57In the "C" locale 58.Fn isblank 59successful test is limited to this characters only. 60The value of the argument must be representable as an 61.Vt "unsigned char" 62or the value of 63.Dv EOF . 64.Sh RETURN VALUES 65The 66.Fn isblank 67function returns zero if the character tests false and 68returns non-zero if the character tests true. 69.Sh COMPATIBILITY 70The 71.Bx 4.4 72extension of accepting arguments outside of the range of the 73.Vt "unsigned char" 74type in locales with large character sets is considered obsolete 75and may not be supported in future releases. 76The 77.Fn iswblank 78function should be used instead. 79.Sh SEE ALSO 80.Xr ctype 3 , 81.Xr iswblank 3 , 82.Xr ascii 7 83.Sh STANDARDS 84The 85.Fn isblank 86function 87conforms to 88.St -isoC-99 . 89