1.\" $OpenBSD: strspn.3,v 1.11 2013/06/05 03:39:23 tedu Exp $ 2.\" 3.\" Copyright (c) 1990, 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.\" Chris Torek and the American National Standards Committee X3, 8.\" on Information 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: June 5 2013 $ 35.Dt STRSPN 3 36.Os 37.Sh NAME 38.Nm strspn 39.Nd span a string 40.Sh SYNOPSIS 41.In string.h 42.Ft size_t 43.Fn strspn "const char *s" "const char *charset" 44.Sh DESCRIPTION 45The 46.Fn strspn 47function spans the initial part of the NUL-terminated string 48.Fa s 49as long as the characters from 50.Fa s 51occur in string 52.Fa charset . 53.Sh RETURN VALUES 54The 55.Fn strspn 56function returns the number of characters spanned. 57.Sh EXAMPLES 58The following call to 59.Fn strspn 60will return 3, since the first three characters of string 61.Fa s 62are part of string 63.Fa charset : 64.Bd -literal -offset indent 65char *s = "foobar"; 66char *charset = "of"; 67size_t span; 68 69span = strspn(s, charset); 70.Ed 71.Sh SEE ALSO 72.Xr memchr 3 , 73.Xr strchr 3 , 74.Xr strcspn 3 , 75.Xr strpbrk 3 , 76.Xr strrchr 3 , 77.Xr strsep 3 , 78.Xr strstr 3 , 79.Xr strtok 3 , 80.Xr wcsspn 3 81.Sh STANDARDS 82The 83.Fn strspn 84function conforms to 85.St -ansiC . 86.Sh HISTORY 87The 88.Fn strspn 89function first appeared in 90.At III 91and was reimplemented for 92.Bx 4.3 Tahoe . 93