Add fallback implementation of strndup()

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Jeremy Huddleston <jeremyhu@apple.com>
Linux test code fixed by: Keith Packard <keithp@keithp.com>

2 files changed, 53 insertions, 0 deletions

diff --git a/os/Makefile.am b/os/Makefile.am
index ef9ecddcf..8dd809531 100644
--- a/os/Makefile.am
+++ b/os/Makefile.am
@@ -41,6 +41,10 @@ if NEED_STRLCAT
 libos_la_SOURCES += $(STRLCAT_SRCS)
 endif
 
+if NEED_STRNDUP
+libos_la_SOURCES += $(STRNDUP_SRCS)
+endif
+
 EXTRA_DIST = $(SECURERPC_SRCS) $(INTERNALMALLOC_SRCS) \
      $(XDMCP_SRCS) $(STRLCAT_SRCS)
 
diff --git a/os/strndup.c b/os/strndup.c
new file mode 100644
index 000000000..bf8e982d4
--- /dev/null
+++ b/os/strndup.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 1988, 1993
+ *	The Regents of the University of California.  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.
+ * 4. 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.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include "os.h"
+
+char *
+strndup(const char *str, size_t n)
+{
+	size_t len;
+	char *copy;
+
+	for (len = 0; len < n && str[len]; len++)
+		continue;
+
+	if ((copy = malloc(len + 1)) == NULL)
+		return (NULL);
+	memcpy(copy, str, len);
+	copy[len] = '\0';
+	return (copy);
+}