.\" $OpenBSD: strcspn.3,v 1.11 2013/06/05 03:39:23 tedu Exp $ .\" .\" Copyright (c) 1990, 1991 The Regents of the University of California. .\" All rights reserved. .\" .\" This code is derived from software contributed to Berkeley by .\" Chris Torek and the American National Standards Committee X3, .\" on Information Processing Systems. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .Dd $Mdocdate: June 5 2013 $ .Dt STRCSPN 3 .Os .Sh NAME .Nm strcspn .Nd span the complement of a string .Sh SYNOPSIS .In string.h .Ft size_t .Fn strcspn "const char *s" "const char *charset" .Sh DESCRIPTION The .Fn strcspn function spans the initial part of the NUL-terminated string .Fa s as long as the characters from .Fa s do not occur in string .Fa charset (it spans the .Em complement of .Fa charset ) . .Sh RETURN VALUES The .Fn strcspn function returns the number of characters spanned. .Sh EXAMPLES The following call to .Fn strcspn will return 3, since the first three characters of string .Fa s do not occur in string .Fa charset : .Bd -literal -offset indent char *s = "foobar"; char *charset = "bar"; size_t span; span = strcspn(s, charset); .Ed .Pp The following removes the first (if any) newline character from string .Fa line . This is useful for trimming the newline after a .Xr fgets 3 call. .Bd -literal -offset indent char line[BUFSIZ]; if (fgets(line, sizeof(line), fp) != NULL) line[strcspn(line, "\en")] = '\e0'; .Ed .Sh SEE ALSO .Xr memchr 3 , .Xr strchr 3 , .Xr strpbrk 3 , .Xr strrchr 3 , .Xr strsep 3 , .Xr strspn 3 , .Xr strstr 3 , .Xr strtok 3 , .Xr wcscspn 3 .Sh STANDARDS The .Fn strcspn function conforms to .St -ansiC . .Sh HISTORY The .Fn strcspn function first appeared in .At III and was reimplemented for .Bx 4.3 Tahoe .