Reimplement and bugfix some path functions

source/environment/include/environment/environment_variable_path.h

@@ -52,7 +52,31 @@ extern "C" {
 
 /* -- Methods -- */
 
-ENVIRONMENT_API char *environment_variable_path_create(const char *name, const char *default_path, size_t default_path_size, size_t *env_size);
+/**
+ * @brief
+ *   If the value of `name` exists as an environment variable, return a live string of its value, otherwise return a live value of `default_path` or "/".
+ *
+ *   `name` should not be `NULL`.
+ *
+ *   If `default_path` is not `NULL`, `default_path_size` must be set to <= the length (including 0-terminator) of the `default_path` string.
+ *
+ *   If `env_size` is not `NULL`, the length (including 0-terminator) of the returned string will be set to it
+ * @param[in] name
+ *   The environment variable name to look up.
+ *
+ * @param[in] default_path
+ *   If the environment variable value is not found, the value to return instead.
+ *
+ * @param[in] default_path_size
+ *   The length (including 0-terminator) of `default_path` in chars.
+ *
+ * @param[out] env_size
+ *   Pointer to a size_t to write the length of the returned string to (optional).
+ *
+ * @return
+ *   The allocated string containing the environment variable value or the default or "/".
+ */
+ENVIRONMENT_API char *environment_variable_path_create(const char *const name, const char *const default_path, const size_t default_path_size, size_t *const env_size);
 
 ENVIRONMENT_API void environment_variable_path_destroy(char *variable_path);
 

source/environment/source/environment_variable_path.c

@@ -43,61 +43,32 @@
 
 /* -- Methods -- */
 
-char *environment_variable_path_create(const char *name, const char *default_path, size_t default_path_size, size_t *env_size)
+char *environment_variable_path_create(const char *const name, const char *const default_path, const size_t default_path_size, size_t *const env_size)
 {
-	const char *path_ptr = getenv(name);
-	char *path;
-	size_t length, size, last, end;
-
-	if (path_ptr == NULL)
-	{
-		if (default_path == NULL)
-		{
-			static const char empty_path[] = "";
-
-			default_path = empty_path;
-			default_path_size = sizeof(empty_path);
-		}
-
-		path_ptr = default_path;
-		length = default_path_size - 1;
-	}
-	else
-	{
-		length = strlen(path_ptr);
-	}
-
-	last = length - 1;
-
-	if (ENVIRONMENT_VARIABLE_PATH_SEPARATOR(path_ptr[last]))
+	const char *value = getenv(name);
+	size_t size;
+	if (value)
+		size = strlen(value) + 1;
+	else if (default_path)
 	{
-		end = length;
-		size = length + 1;
+		value = default_path;
+		size = default_path_size;
 	}
 	else
 	{
-		last = length;
-		end = length + 1;
-		size = length + 2;
+		value = ENVIRONMENT_VARIABLE_PATH_SEPARATOR_STR;
+		size = sizeof(ENVIRONMENT_VARIABLE_PATH_SEPARATOR_STR);
 	}
-
-	path = malloc(sizeof(char) * size);
-
-	if (path == NULL)
-	{
-		return NULL;
-	}
-
-	strncpy(path, path_ptr, length);
-
-	path[last] = ENVIRONMENT_VARIABLE_PATH_SEPARATOR_C;
-	path[end] = '\0';
-
-	if (env_size != NULL)
-	{
-		*env_size = size;
-	}
-
+	size_t alloc_size = size;
+	if (size > 1)
+		alloc_size += !ENVIRONMENT_VARIABLE_PATH_SEPARATOR(value[size - 2]);
+	char *const path = malloc(sizeof(char) * alloc_size);
+	memcpy(path, value, sizeof(char) * size);
+	if (size > 1)
+		path[alloc_size - 2] = ENVIRONMENT_VARIABLE_PATH_SEPARATOR_C;
+	path[alloc_size - 1] = '\0';
+	if (env_size)
+		*env_size = alloc_size;
 	return path;
 }
 

source/portability/include/portability/portability_path.h

@@ -109,9 +109,55 @@ extern "C" {
 
 /* -- Methods -- */
 
-PORTABILITY_API size_t portability_path_get_name(const char *path, size_t path_size, char *name, size_t name_size);
+/**
+ * @brief
+ *   Get the file name portion out of a path and strip away the file extension if any.
+ *
+ *   If `path` is NULL this will return an empty string.
+ *
+ *   If `name` is NULL or `name_size is 0 this will return the size it requires in order to write `name`.
+ *
+ *   If `path` or `name` are not NULL, then `path_size` or `name_size`, respectively, must be set to <= the length (including 0-terminator) of the memory regions pointed to by `path` and `name`.
+ * @param[in] path
+ *   The full path to extract the name from.
+ * @param[in] path_size
+ *   The length (including 0-terminator) of `path` in chars.
+ * @param[out] name
+ *   The memory location to write the extracted name to. If `NULL` the size required will be returned instead of the size written.
+ * @param[in] name_size
+ *   The size of the memory location pointed to by `name`.
+ * @return
+ *   The size of the name.
+ */
+PORTABILITY_API size_t portability_path_get_name(const char *const path, const size_t path_size, char *const name, const size_t name_size);
 
-PORTABILITY_API size_t portability_path_get_name_canonical(const char *path, size_t path_size, char *name, size_t name_size);
+/**
+ * @brief
+ *   Get the file name portion out of a path and strip away any amount of file extensions.
+ *
+ *   When called with `"/foo/bar.baz.qux"`:
+ *
+ *     - `portability_path_get_name` will produce the string `"bar.baz"`
+ *
+ *     - `portability_path_get_name_canonical` will produce the string `"bar"`
+ *
+ *   If `path` is NULL this will return an empty string.
+ *
+ *   If `name` is NULL or `name_size is 0 this will return the size it requires in order to write `name`.
+ *
+ *   If `path` or `name` are not NULL, then `path_size` or `name_size`, respectively, must be set to <= the length (including 0-terminator) of the memory regions pointed to by `path` and `name`.
+ * @param[in] path
+ *   The full path to extract the name from.
+ * @param[in] path_size
+ *   The length (including 0-terminator) of `path` in chars.
+ * @param[out] name
+ *   The memory location to write the extracted name to. If `NULL` the size required will be returned instead of the size written.
+ * @param[in] name_size
+ *   The size of the memory location pointed to by `name`.
+ * @return
+ *   The size of the name.
+ */
+PORTABILITY_API size_t portability_path_get_name_canonical(const char *const path, const size_t path_size, char *const name, const size_t name_size);
 
 PORTABILITY_API size_t portability_path_get_fullname(const char *path, size_t path_size, char *name, size_t name_size);
 

source/portability/source/portability_path.c

@@ -25,107 +25,81 @@
 /* Define separator checking for any platform */
 #define PORTABILITY_PATH_SEPARATOR_ALL(chr) (chr == '\\' || chr == '/')
 
-size_t portability_path_get_name(const char *path, size_t path_size, char *name, size_t name_size)
+static size_t basename_offset(const char *const path, const size_t path_size)
 {
-	size_t i, count, last;
-
-	if (path == NULL || name == NULL)
-	{
-		return 0;
-	}
-
-	for (i = 0, count = 0, last = 0; path[i] != '\0' && i < path_size && count < name_size; ++i)
-	{
-		name[count++] = path[i];
-
-		if (PORTABILITY_PATH_SEPARATOR(path[i]))
-		{
-			count = 0;
-		}
-		else if (path[i] == '.')
-		{
-			if (i > 0 && path[i - 1] == '.')
-			{
-				last = 0;
-				count = 0;
-			}
-			else
-			{
-				if (count > 0)
-				{
-					last = count - 1;
-				}
-				else
-				{
-					last = 0;
-				}
-			}
-		}
-	}
+	size_t offset = path_size;
+	for (; offset != 0; offset--)
+		if (PORTABILITY_PATH_SEPARATOR(path[offset - 1]))
+			break;
+	return offset;
+}
 
-	if ((last == 0 && count > 1) || last > count)
+size_t portability_path_get_name(const char *const path, const size_t path_size, char *const name, const size_t name_size)
+{
+	if (path == NULL)
 	{
-		last = count;
+		if (name == NULL || name_size == 0)
+			return 0;
+		name[0] = '\0';
+		return 1;
 	}
-
-	name[last] = '\0';
-
-	return last + 1;
+	// find rightmost path separator
+	const size_t name_start = basename_offset(path, path_size);
+	// Find rightmost dot
+	size_t rightmost_dot = path_size;
+	for (; rightmost_dot != name_start; rightmost_dot--)
+		if (path[rightmost_dot - 1] == '.')
+			break;
+	// No dots found, or name starts with dot and is non-empty, use whole name
+	if (rightmost_dot == name_start || (rightmost_dot == name_start + 1 && rightmost_dot != path_size - 1))
+		rightmost_dot = path_size - 1;
+	// remove all consecutive dots at the end
+	while (rightmost_dot != name_start && path[rightmost_dot - 1] == '.')
+		rightmost_dot--;
+	const size_t length = rightmost_dot - name_start;
+	const size_t size = length + 1;
+	// Return required size
+	if (name == NULL || size > name_size)
+		return size;
+	if (length)
+		memcpy(name, path + name_start, length);
+	name[length] = '\0';
+	return size;
 }
 
-size_t portability_path_get_name_canonical(const char *path, size_t path_size, char *name, size_t name_size)
+size_t portability_path_get_name_canonical(const char *const path, const size_t path_size, char *const name, const size_t name_size)
 {
-	if (path == NULL || name == NULL)
+	if (path == NULL)
 	{
-		return 0;
+		if (name == NULL || name_size == 0)
+			return 0;
+		name[0] = '\0';
+		return 1;
 	}
-
-	size_t i, count, last;
-
-	for (i = 0, count = 0, last = 0; path[i] != '\0' && i < path_size && count < name_size; ++i)
-	{
-		name[count++] = path[i];
-
-		if (PORTABILITY_PATH_SEPARATOR(path[i]))
-		{
-			count = 0;
-		}
-		else if (path[i] == '.')
-		{
-			if (i > 0 && path[i - 1] == '.')
-			{
-				last = 0;
-				count = 0;
-			}
-			else
-			{
-				if (count > 0)
-				{
-					last = count - 1;
-				}
-				else
-				{
-					last = 0;
-				}
-
-				/* This function is the same as portability_path_get_name but
-				returns the name of the file without any extension, for example:
-					- portability_path_get_name of libnode.so.72 is libnode.so
-					- portability_path_get_name_canonical of libnode.so.72 is libnode
-				*/
+	// find rightmost path separator
+	const size_t name_start = basename_offset(path, path_size);
+	// find leftmost dot
+	size_t leftmost_dot = name_start;
+	for (; leftmost_dot < path_size; leftmost_dot++)
+		if (path[leftmost_dot] == '.')
+			break;
+	// No dots found, use whole name
+	if (leftmost_dot == path_size)
+		leftmost_dot--;
+	// name starts with dot, use the following dot instead
+	if (leftmost_dot == name_start)
+		for (leftmost_dot = name_start + 1; leftmost_dot < path_size; leftmost_dot++)
+			if (path[leftmost_dot] == '.')
 				break;
-			}
-		}
-	}
-
-	if (last == 0 && count > 1)
-	{
-		last = count;
-	}
-
-	name[last] = '\0';
-
-	return last + 1;
+	const size_t length = leftmost_dot - name_start;
+	const size_t size = length + 1;
+	// Return required size
+	if (name == NULL || size > name_size)
+		return size;
+	if (length)
+		memcpy(name, path + name_start, length);
+	name[length] = '\0';
+	return size;
 }
 
 size_t portability_path_get_fullname(const char *path, size_t path_size, char *name, size_t name_size)