From 3ec29ae85ea44c459b342d1439c89a2ab2c992af Mon Sep 17 00:00:00 2001
From: Erik van der Kouwe <erik@minix3.org>
Date: Mon, 25 Jan 2010 18:12:28 +0000
Subject: [PATCH] Add dirname function

---
 lib/other/dirname.c | 29 +++++++++++++++++++++
 man/man3/dirname.3  | 19 ++++++++++++++
 test/test43.c       | 61 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 109 insertions(+)
 create mode 100755 lib/other/dirname.c
 create mode 100755 man/man3/dirname.3

diff --git a/lib/other/dirname.c b/lib/other/dirname.c
new file mode 100755
index 000000000..1a578aed5
--- /dev/null
+++ b/lib/other/dirname.c
@@ -0,0 +1,29 @@
+#include <libgen.h>
+#include <string.h>
+
+/* based on http://www.opengroup.org/onlinepubs/009695399/functions/dirname.html */
+char *dirname(char *path)
+{
+	char *pathend;
+
+	/* remove leading slash(es) except root */
+	pathend = path + strlen(path) - 1;
+	while (pathend > path && *pathend == '/')
+		pathend--;
+	
+	/* remove last path component */
+	while (pathend >= path && *pathend != '/')
+		pathend--;
+
+	/* remove slash(es) before last path component except root */
+	while (pathend > path && *pathend == '/')
+		pathend--;
+
+	/* special case: no slashes */
+	if (pathend < path)
+		return ".";
+
+	/* truncate and return string */
+	pathend[1] = 0;
+	return path;
+}
diff --git a/man/man3/dirname.3 b/man/man3/dirname.3
new file mode 100755
index 000000000..30c9c0a96
--- /dev/null
+++ b/man/man3/dirname.3
@@ -0,0 +1,19 @@
+.TH DIRNAME 3
+.SH NAME
+dirname \- determine name of containing directory
+.SH SYNOPSIS
+.nf
+.ft B
+#include <libgen.h>
+
+char *dirname(char *\fIpath\fP);
+.SH DESCRIPTION
+The dirname function returns the name of the directory containing \fIpath\fP.
+If the path does not contain slashes, the string "." is returned. Trailing 
+slashes are ignored.
+.SH "SEE ALSO"
+.BR basename (3).
+.SH NOTES
+This function may, but need not, overwrite the buffer passed to it.
+Although MINIX' implementation of this function is re-entrant, POSIX does not
+guarantee this property and portable programs should not rely on it.
diff --git a/test/test43.c b/test/test43.c
index 8ff3534eb..0e4d509ab 100644
--- a/test/test43.c
+++ b/test/test43.c
@@ -3,6 +3,7 @@
 #include <assert.h>
 #include <dirent.h>
 #include <errno.h>
+#include <libgen.h>
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -328,6 +329,36 @@ static void cleanup(const char *path)
 	if (rmdir(path) < 0) ERR;
 }
 
+static void test_dirname(const char *path, const char *exp)
+{
+	char buffer[PATH_MAX];
+	int i, j;
+	size_t pathlen = strlen(path);
+	char *pathout;
+
+	assert(pathlen + 3 < PATH_MAX);
+
+	/* try with no, one or two trailing slashes */
+	for (i = 0; i < 3; i++)
+	{
+		/* no trailing slashes for empty string */
+		if (pathlen < 1 && i > 0)
+			continue;
+			
+		/* prepare buffer */
+		strcpy(buffer, path);
+		for (j = 0; j < i; j++)
+			buffer[pathlen + j] = '/';
+	
+		buffer[pathlen + i] = 0;
+	
+		/* perform test */
+		pathout = dirname(buffer);
+		if (strcmp(pathout, exp) != 0)
+			ERR;
+	}
+}
+
 int main(int argc, char **argv)
 {
 	char buffer1[PATH_MAX + 1], buffer2[PATH_MAX + 1];
@@ -358,6 +389,36 @@ int main(int argc, char **argv)
 	/* delete the symlinks */
 	cleanup(addbasepath(buffer1, PATH_BASE));
 
+	/* also test dirname */
+	test_dirname("", ".");	
+	test_dirname(".", ".");	
+	test_dirname("..", ".");	
+	test_dirname("x", ".");	
+	test_dirname("xy", ".");	
+	test_dirname("x/y", "x");	
+	test_dirname("xy/z", "xy");	
+	test_dirname("x/yz", "x");	
+	test_dirname("ab/cd", "ab");	
+	test_dirname("x//y", "x");	
+	test_dirname("xy//z", "xy");	
+	test_dirname("x//yz", "x");	
+	test_dirname("ab//cd", "ab");	
+	test_dirname("/", "/");	
+	test_dirname("/x", "/");	
+	test_dirname("/xy", "/");	
+	test_dirname("/x/y", "/x");	
+	test_dirname("/xy/z", "/xy");	
+	test_dirname("/x/yz", "/x");	
+	test_dirname("/ab/cd", "/ab");	
+	test_dirname("/x//y", "/x");	
+	test_dirname("/xy//z", "/xy");	
+	test_dirname("/x//yz", "/x");	
+	test_dirname("/ab//cd", "/ab");	
+	test_dirname("/usr/src", "/usr");	
+	test_dirname("/usr/src/test", "/usr/src");	
+	test_dirname("usr/src", "usr");	
+	test_dirname("usr/src/test", "usr/src");	
+
 	/* done */
 	quit();
 	return(-1);	/* impossible */
-- 
2.44.0