1 files changed, 70 insertions, 0 deletions
diff --git a/lib/libc/gen/dirname.c b/lib/libc/gen/dirname.c
new file mode 100644
index 000000000000..7157fec23630
--- /dev/null
+++ b/lib/libc/gen/dirname.c
@@ -0,0 +1,70 @@
+/*-
+ * Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
+ *
+ * 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 <libgen.h>
+#include <string.h>
+
+char *
+(dirname)(char *path)
+{
+	char *end;
+
+	/*
+	 * If path is a null pointer or points to an empty string,
+	 * dirname() shall return a pointer to the string ".".
+	 */
+	if (path == NULL || *path == '\0')
+		return (__DECONST(char *, "."));
+
+	/* Find end of last pathname component. */
+	end = path + strlen(path);
+	while (end > path + 1 && *(end - 1) == '/')
+		--end;
+
+	/* Strip off the last pathname component. */
+	while (end > path && *(end - 1) != '/')
+		--end;
+
+	/*
+	 * If path does not contain a '/', then dirname() shall return a
+	 * pointer to the string ".".
+	 */
+	if (end == path) {
+		path[0] = '.';
+		path[1] = '\0';
+		return (path);
+	}
+
+	/*
+	 * Remove trailing slashes from the resulting directory name. Ensure
+	 * that at least one character remains.
+	 */
+	while (end > path + 1 && *(end - 1) == '/')
+		--end;
+
+	/* Null terminate directory name and return it. */
+	*end = '\0';
+	return (path);
+}