[PATCH 1/2] Introduce the function strip_path_suffix()

From

Johannes Schindelin <johannes.schindelin@gmx.de>

Date

Feb 18, 2009, 15:11 UTC

Message-ID

<7b5ee74d497bbb7144b8683725cd83c8bbd33f9a.1234969572u.git.johannes.schindelin@gmx.de>

In-Reply-To

<cover.1234969572u.git.johannes.schindelin@gmx.de>

Arbitrary runs of directory separators ("slashes") are assumed identical.

Example:

	strip_path_suffix("C:\\msysgit/\\libexec\\git-core",
		"libexec///git-core", &prefix)

will set prefix to "C:\\msysgit" and return 0.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 cache.h |    2 ++
 path.c  |   33 +++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/cache.h b/cache.h
index 4e28c24..2186143 100644
--- a/cache.h
+++ b/cache.h
@@ -629,6 +629,8 @@ const char *make_nonrelative_path(const char *path);
 const char *make_relative_path(const char *abs, const char *base);
 int normalize_path_copy(char *dst, const char *src);
 int longest_ancestor_length(const char *path, const char *prefix_list);
+int strip_path_suffix(const char *path, const char *suffix,
+		const char **prefix);
 
 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 extern int sha1_object_info(const unsigned char *, unsigned long *);
diff --git a/path.c b/path.c
index 4b9107f..947e5b7 100644
--- a/path.c
+++ b/path.c
@@ -499,3 +499,36 @@ int longest_ancestor_length(const char *path, const char *prefix_list)
 
 	return max_len;
 }
+
+/* strip arbitrary amount of directory separators at end of path */
+static inline int chomp_trailing_dir_sep(const char *path, int len)
+{
+	while (len && is_dir_sep(path[len - 1]))
+		len--;
+	return len;
+}
+
+/* sets prefix if the suffix matches */
+int strip_path_suffix(const char *path, const char *suffix, const char **prefix)
+{
+	int path_len = strlen(path), suffix_len = strlen(suffix);
+
+	while (suffix_len) {
+		if (!path_len)
+			return 1;
+
+		if (is_dir_sep(path[path_len - 1])) {
+			if (!is_dir_sep(suffix[suffix_len - 1]))
+				return 1;
+			path_len = chomp_trailing_dir_sep(path, path_len);
+			suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
+		}
+		else if (path[--path_len] != suffix[--suffix_len])
+			return 1;
+	}
+
+	if (path_len && !is_dir_sep(path[path_len - 1]))
+		return 1;
+	*prefix = xstrndup(path, chomp_trailing_dir_sep(path, path_len));
+	return 0;
+}

-- 
1.6.1.1.825.g72a9f