From: Michael Tremer <michael.tremer@ipfire.org>
Date: Thu, 16 Mar 2023 15:54:51 +0000 (+0000)
Subject: util: Implement a simple path matching function that supports **
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6871e28d5bb7ac2d2fbcb168a830474ab16a8b14;p=people%2Fstevee%2Fpakfire.git

util: Implement a simple path matching function that supports **

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/include/pakfire/util.h b/src/libpakfire/include/pakfire/util.h
index 18b1e5b7..661fff4d 100644
--- a/src/libpakfire/include/pakfire/util.h
+++ b/src/libpakfire/include/pakfire/util.h
@@ -37,6 +37,7 @@
 char* pakfire_unquote_in_place(char* s);
 
 int pakfire_path_exists(const char* path);
+int pakfire_path_match(const char* p, const char* s);
 time_t pakfire_path_age(const char* path);
 
 int pakfire_path_strip_extension(char* path);
diff --git a/src/libpakfire/util.c b/src/libpakfire/util.c
index 4711a1d8..a972e96b 100644
--- a/src/libpakfire/util.c
+++ b/src/libpakfire/util.c
@@ -149,6 +149,88 @@ int pakfire_path_exists(const char* path) {
 	return !access(path, F_OK);
 }
 
+/*
+	This function will handle any stars in the pattern matching
+
+	stars will be set to non-zero if we encountered a double star
+*/
+static int __pakfire_path_match_star(const char* p, const char* s) {
+	unsigned int stars = 0;
+
+	// Count how many stars we found
+	while (p && *p == '*') {
+		// Consume the star
+		p++;
+
+		// Increment the counter
+		stars++;
+	}
+
+	// We do not allow more than two stars
+	if (stars > 2) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	// Consume the string...
+	for (; *s; s++) {
+		switch (*s) {
+			// Found slash!
+			case '/':
+				if (stars == 1)
+					return pakfire_path_match(p, s);
+
+				// Otherwise fall through
+
+			// Read as many characters as possible
+			default:
+				continue;
+		}
+	}
+
+	// If we reached the end of the string, * has consumed everything
+	return 1;
+}
+
+/*
+	This is our custom implementation of fnmatch()
+	which supports ** and stops at slashes.
+*/
+int pakfire_path_match(const char* p, const char* s) {
+	// Empty pattern matches nothing
+	if (!*p)
+		return 0;
+
+	// Consume the pattern and string...
+	for (; *p; p++, s++) {
+		switch (*p) {
+			// Match any character
+			case '?':
+				// No match if we reached the end
+				if (!*s)
+					return 0;
+
+				continue;
+
+			// Match multiple characters
+			case '*':
+				return __pakfire_path_match_star(p, s);
+
+			// All other characters
+			default:
+				// Character matches
+				if (*s == *p)
+					continue;
+
+				// No match
+				return 0;
+		}
+	}
+
+	// We reached the end of the string and all characters matched
+	return 1;
+}
+
 time_t pakfire_path_age(const char* path) {
 	struct stat st;
 
diff --git a/tests/libpakfire/util.c b/tests/libpakfire/util.c
index 70f411b7..37ec2685 100644
--- a/tests/libpakfire/util.c
+++ b/tests/libpakfire/util.c
@@ -72,10 +72,36 @@ FAIL:
 	return EXIT_FAILURE;
 }
 
+static int test_path_match(const struct test* t) {
+	// Simple string match
+	ASSERT_TRUE(pakfire_path_match("/abc", "/abc"));
+
+	// Simple negative string match
+	ASSERT_FALSE(pakfire_path_match("/abc", "/def"));
+
+	// Simple star match
+	ASSERT_TRUE(pakfire_path_match("/usr/*", "/usr/bin"));
+	ASSERT_FALSE(pakfire_path_match("/usr/*", "/usr/bin/bash"));
+
+	// Double star match
+	ASSERT_TRUE(pakfire_path_match("/usr/**", "/usr/bin"));
+	ASSERT_TRUE(pakfire_path_match("/usr/**", "/usr/bin/bash"));
+
+	// Tripe star matches are invalid
+	ASSERT_ERRNO(pakfire_path_match("/usr/***", "/usr/bin"), EINVAL);
+	ASSERT_ERRNO(pakfire_path_match("/usr/***", "/usr/bin/bash"), EINVAL);
+
+	return EXIT_SUCCESS;
+
+FAIL:
+	return EXIT_FAILURE;
+}
+
 int main(int argc, const char* argv[]) {
 	testsuite_add_test(test_basename);
 	testsuite_add_test(test_dirname);
 	testsuite_add_test(test_mkdir);
+	testsuite_add_test(test_path_match);
 
 	return testsuite_run(argc, argv);
 }