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: head/lib/libc/locale/isblank.3 248803 2013-03-27 21:31:40Z jilles $ 30.\" 31.Dd December 25, 2013 32.Dt ISBLANK 3 33.Os 34.Sh NAME 35.Nm isblank , 36.Nm isblank_l 37.Nd space or tab character test 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In ctype.h 42.Ft int 43.Fn isblank "int c" 44.Ft int 45.Fn isblank_l "int c" "locale_t locale" 46.Sh DESCRIPTION 47The 48.Fn isblank 49and 50.Fn isblank_l 51functions test for a space or tab character. 52For any locale, this includes the following standard characters: 53.Bl -column XXXX 54.It Do \et Dc Ta Dq " " 55.El 56.Pp 57In the "C" locale, a successful 58.Fn isblank 59test is limited to these characters only. 60The value of the argument must be representable as an 61.Vt "unsigned char" 62or the value of 63.Dv EOF . 64.Pp 65The 66.Fn isblank_l 67function takes an explicit 68.Fa locale 69argument, whereas the 70.Fn isblank 71function uses the current global or per-thread locale. 72.Sh RETURN VALUES 73The 74.Fn isblank 75and 76.Fn isblank_l 77functions return zero if the character tests false and 78returns non-zero if the character tests true. 79.Sh COMPATIBILITY 80The 81.Bx 4.4 82extension of accepting arguments outside of the range of the 83.Vt "unsigned char" 84type in locales with large character sets is considered obsolete 85and may not be supported in future releases. 86The 87.Fn iswblank 88and 89.Fn iswblank_l 90function should be used instead. 91.Sh SEE ALSO 92.Xr ctype 3 , 93.Xr iswblank 3 , 94.Xr iswblank_l 3 , 95.Xr xlocale 3 , 96.Xr ascii 7 97.Sh STANDARDS 98The 99.Fn isblank 100function 101conforms to 102.St -isoC-99 . 103The 104.Fn isblank_l 105function conforms to 106.St -p1003.1-2008 . 107