1.\" $OpenBSD: strcspn.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 STRCSPN 3 36.Os 37.Sh NAME 38.Nm strcspn 39.Nd span the complement of a string 40.Sh SYNOPSIS 41.In string.h 42.Ft size_t 43.Fn strcspn "const char *s" "const char *charset" 44.Sh DESCRIPTION 45The 46.Fn strcspn 47function spans the initial part of the NUL-terminated string 48.Fa s 49as long as the characters from 50.Fa s 51do not occur in string 52.Fa charset 53(it spans the 54.Em complement 55of 56.Fa charset ) . 57.Sh RETURN VALUES 58The 59.Fn strcspn 60function returns the number of characters spanned. 61.Sh EXAMPLES 62The following call to 63.Fn strcspn 64will return 3, since the first three characters of string 65.Fa s 66do not occur in string 67.Fa charset : 68.Bd -literal -offset indent 69char *s = "foobar"; 70char *charset = "bar"; 71size_t span; 72 73span = strcspn(s, charset); 74.Ed 75.Pp 76The following removes the first (if any) newline character from string 77.Fa line . 78This is useful for trimming the newline after a 79.Xr fgets 3 80call. 81.Bd -literal -offset indent 82char line[BUFSIZ]; 83 84if (fgets(line, sizeof(line), fp) != NULL) 85 line[strcspn(line, "\en")] = '\e0'; 86.Ed 87.Sh SEE ALSO 88.Xr memchr 3 , 89.Xr strchr 3 , 90.Xr strpbrk 3 , 91.Xr strrchr 3 , 92.Xr strsep 3 , 93.Xr strspn 3 , 94.Xr strstr 3 , 95.Xr strtok 3 , 96.Xr wcscspn 3 97.Sh STANDARDS 98The 99.Fn strcspn 100function conforms to 101.St -ansiC . 102.Sh HISTORY 103The 104.Fn strcspn 105function first appeared in 106.At III 107and was reimplemented for 108.Bx 4.3 Tahoe . 109