Add strchrnul(), a GNU function similar to strchr(), except that it returns

a pointer to the end of the string, rather than NULL, if the character was
not found.

Approved by:	theraven

include/string.h

@@ -74,6 +74,9 @@ char	*strcasestr(const char *, const char *) __pure;
 #endif
 char	*strcat(char * __restrict, const char * __restrict);
 char	*strchr(const char *, int) __pure;
+#if defined(_GNU_SOURCE)
+char	*strchrnul(const char*, int) __pure;
+#endif
 int	 strcmp(const char *, const char *) __pure;
 int	 strcoll(const char *, const char *);
 char	*strcpy(char * __restrict, const char * __restrict);

lib/libc/string/Makefile.inc

@@ -10,9 +10,9 @@ MISRCS+=bcmp.c bcopy.c bzero.c ffs.c ffsl.c ffsll.c fls.c flsl.c flsll.c \
 	memccpy.c memchr.c memrchr.c memcmp.c \
 	memcpy.c memmem.c memmove.c memset.c \
 	stpcpy.c stpncpy.c strcasecmp.c \
-	strcat.c strcasestr.c strchr.c strcmp.c strcoll.c strcpy.c strcspn.c \
+	strcat.c strcasestr.c strchr.c strchrnul.c strcmp.c strcoll.c strcpy.c\
-	strdup.c strerror.c strlcat.c strlcpy.c strlen.c strmode.c strncat.c \
+	strcspn.c strdup.c strerror.c strlcat.c strlcpy.c strlen.c strmode.c \
-	strncmp.c strncpy.c strndup.c strnlen.c strnstr.c \
+	strncat.c strncmp.c strncpy.c strndup.c strnlen.c strnstr.c \
 	strpbrk.c strrchr.c strsep.c strsignal.c strspn.c strstr.c strtok.c \
 	strxfrm.c swab.c wcpcpy.c wcpncpy.c wcscasecmp.c wcscat.c \
 	wcschr.c wcscmp.c wcscoll.c wcscpy.c wcscspn.c wcsdup.c \

lib/libc/string/Symbol.map

@@ -94,6 +94,7 @@ FBSD_1.1 {
 FBSD_1.3 {
 	strcasecmp_l;
 	strcasestr_l;
+	strchrnul;
 	strncasecmp_l;
 	wcswidth_l;
 	wcwidth_l;

lib/libc/string/strchr.3

@@ -32,11 +32,11 @@
 .\"     @(#)strchr.3	8.2 (Berkeley) 4/19/94
 .\" $FreeBSD$
 .\"
-.Dd April 19, 1994
+.Dd February 13, 2013
 .Dt STRCHR 3
 .Os
 .Sh NAME
-.Nm strchr , strrchr
+.Nm strchr , strrchr , strchrnul
 .Nd locate character in string
 .Sh LIBRARY
 .Lb libc
@@ -46,6 +46,8 @@
 .Fn strchr "const char *s" "int c"
 .Ft "char *"
 .Fn strrchr "const char *s" "int c"
+.Ft "char *"
+.Fn strchrnul "const char *s" "int c"
 .Sh DESCRIPTION
 The
 .Fn strchr
@@ -69,6 +71,18 @@ function is identical to
 .Fn strchr
 except it locates the last occurrence of
 .Fa c .
+.Pp
+The
+.Fn strchrnul
+function is identical to
+.Fn strchr
+except that if
+.Fa c
+is not found in
+.Fa s
+a pointer to the terminating
+.Ql \e0
+is returned.
 .Sh RETURN VALUES
 The functions
 .Fn strchr
@@ -77,6 +91,11 @@ and
 return a pointer to the located character, or
 .Dv NULL
 if the character does not appear in the string.
+.Pp
+.Fn strchrnul
+returns a pointer to the terminating
+.Ql \e0
+if the character does not appear in the string.
 .Sh SEE ALSO
 .Xr memchr 3 ,
 .Xr memmem 3 ,
@@ -94,3 +113,11 @@ and
 .Fn strrchr
 conform to
 .St -isoC .
+The
+.Fn strchrnul
+is a GNU extension .
+.Sh History
+The
+.Fn strchrnul
+function first appeared in glibc 2.1.1 and was added in
+.Fx 10.0 .

lib/libc/string/strchrnul.c

@@ -0,0 +1,48 @@
+/*-
+ * Copyright (c) 2013 Niclas Zeising
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stddef.h>
+#include <string.h>
+
+__weak_reference(__strchrnul, strchrnul);
+
+char *
+__strchrnul(const char *p, int ch)
+{
+	char c;
+
+	c = ch;
+	for (;; ++p) {
+		if (*p == c || *p == '\0')
+			return ((char *)p);
+	}
+	/* NOTREACHED */
+}
+