From: Michael Tremer <michael.tremer@ipfire.org>
Date: Mon, 6 Jan 2025 21:30:07 +0000 (+0000)
Subject: strings: Create a function to copy a fixed-length string
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4f480453654615896aa744003f17bea1191a1b75;p=people%2Fric9%2Fpakfire.git

strings: Create a function to copy a fixed-length string

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

diff --git a/src/pakfire/string.c b/src/pakfire/string.c
index 9b75effbd..00e8233c7 100644
--- a/src/pakfire/string.c
+++ b/src/pakfire/string.c
@@ -70,6 +70,20 @@ int __pakfire_string_set(char* s, const size_t length, const char* value) {
 	return __pakfire_string_format(s, length, "%s", value);
 }
 
+int __pakfire_string_setn(char* s, const size_t length, const char* value, const size_t l) {
+	// Fail if we don't have enough space
+	if (l >= length)
+		return -ENOBUFS;
+
+	// Copy the data
+	memcpy(s, value, l);
+
+	// Terminate the result buffer
+	s[l] = '\0';
+
+	return l;
+}
+
 int pakfire_string_startswith(const char* s, const char* prefix) {
 	// Validate input
 	if (!s || !prefix)
diff --git a/src/pakfire/string.h b/src/pakfire/string.h
index 16e3d57fb..2fbccd145 100644
--- a/src/pakfire/string.h
+++ b/src/pakfire/string.h
@@ -48,6 +48,10 @@ int __pakfire_string_vformat(char* s, const size_t length,
 	__pakfire_string_set(s, sizeof(s), value)
 int __pakfire_string_set(char* s, const size_t length, const char* value);
 
+#define pakfire_string_setn(s, value, l) \
+	__pakfire_string_setn(s, sizeof(s), value, l)
+int __pakfire_string_setn(char* s, const size_t length, const char* value, const size_t l);
+
 int pakfire_string_startswith(const char* s, const char* prefix);
 int pakfire_string_endswith(const char* s, const char* suffix);
 int pakfire_string_matches(const char* s, const char* pattern);
diff --git a/tests/libpakfire/string.c b/tests/libpakfire/string.c
index bfe4f6acf..56a093cf9 100644
--- a/tests/libpakfire/string.c
+++ b/tests/libpakfire/string.c
@@ -44,6 +44,26 @@ FAIL:
 	return EXIT_FAILURE;
 }
 
+static int test_string_setn(const struct test* t) {
+	char buffer[8];
+
+	// Some test data to copy
+	const char* s1 = "ABCDEFG";
+	const char* s2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+	// Write a string into a buffer which just has just enough space
+	ASSERT(pakfire_string_setn(buffer, s1, strlen(s1)) == strlen(s1));
+	ASSERT_STRING_EQUALS(buffer, s1);
+
+	// Write a string which would not fit
+	ASSERT_ERROR(pakfire_string_setn(buffer, s2, strlen(s2)), ENOBUFS);
+
+	return EXIT_SUCCESS;
+
+FAIL:
+	return EXIT_FAILURE;
+}
+
 static int test_string_startswith(const struct test* t) {
 	ASSERT_TRUE(pakfire_string_startswith("ABC", "A"));
 	ASSERT_FALSE(pakfire_string_startswith("ABC", "B"));
@@ -370,6 +390,7 @@ FAIL:
 
 int main(int argc, const char* argv[]) {
 	testsuite_add_test(test_string_set, 0);
+	testsuite_add_test(test_string_setn, 0);
 	testsuite_add_test(test_string_startswith, 0);
 	testsuite_add_test(test_string_endswith, 0);
 	testsuite_add_test(test_string_matches, 0);