Filesystem Operations for Node-RED

The node-red-contrib-fs is a set of Node-RED nodes for work with the filesystem. The following nodes are available:

Copies or moves files and folders or creates links to them.
Deletes files and folders.
Creates folders.
Lists content of a folder.
Provides details about a file or folder.
Tests if a file or folder is visible, readable or writeable for your flow.

Common Description

Most of the FS nodes have a Path and Filename property which offer very flexible specification of the file you want to use. The user can provide both values as a message, flow or global property, or as a string, or as an environment variable. If the filename is relative, the node combines path and filename together. It is possible to omit path and provide the full specification only in filename. If the filename is relative in this case then the current working folder is used as the path (except creating temporary folder, see FS Make Folder). Examples:

Path: /foo
Filename: bar.txt
/foo/bar.txt

Path: /foo
Filename: /other/bar.txt
/other/bar.txt

Path: /foo/
Filename:
/foo/

Path:
Filename: bar.txt
./bar.txt

All nodes, excpet the FS Access node, produce common Node-RED errors when they meet a problem, therefore it is possible to use the catch node to process errors.

FS Copy/Move/Link Node

Use this node when you need to copy or move file(s) or folder(s), or you need to create a symlink to them.

Operation specifies which filesystem operation to use. All operations have the same parameters. Src Path and Src Filename say what is the source of the selected operation. The standard globbing wild cards *, ?, [] and {} are allowd. Dest Path and Dest Filename say what is the source of the selected operation. If you need to say explicitly that the destination is a folder, please add a folder separator to the end. See path and filename rules in the Common Description section.

If Overwrite dest is checked and the target file alread exists, it will be silently replaced. Otherwise the operation will cause an exception. A folder can not be overwritten. It will cause an exception everytime, regardles of the state of this option. The reason is that this is a dangerous operation. You can accidentaly destroy a large folder tree.

If it is necessary, the missing folders in the destination folder will be created.

FS Remove Node

Use this node if you need to remove file(s) or folder(s).

Path and Filename fields say which file or folder you want to remove. See path and filename rules in the Common Description section. It is possible to use the globbing wild cards to delete multiple targets.

The Recursive option allows to delete a not empty folders. If it is not checked and removing requirest to remove not empty folder, a Node-RED error will be produced.

If Must Exist is checked and the target does not exist, it will produce a Node-RED error. If it is not checked, the unexisting target is silently ignored.

FS MkDir Node

Use this node if you need to create a folder.

Path and Foldername fields say which file or folder you want to create. See path and filename rules in the Common Description section. It is possible to create several levels of folders with the Recursive option.

If Error on Exist is checked and the folder with the requested name already exists, it will cause a Node-RED error. If it is unchecked, the issue is silently ignored.

The Mode field must contain Linux access rights in the octal form.

When you need a temporary folder with a unique name, switch Purpose switcher from regular to temporary. Now you can set Name Prefix instead of Foldername (it is not mandatory). The newly created folder will get a auto-generated unique name prefixed with your Name Prefix.

If the path specification of the temporary folder is relative then the folder will be created in the system temporary folder (usualy /tmp or /var/tmp). It is different compared to all other path specifications which relate to the working folder.

You can choose where you want to store the resultant name with the Result Property field. It works for both the regular and temporary folder. However it is useful for the temporary folder only, as you the new folder name is random.

FS List Node

Use this node if you need to get the list of a folder content.

You can limit listed content with Pattern and Filter fields. The pattern can contain the standard globbing wild cards *, ?, [] and {}. The filter can limit result to only files or folders.

Be careful with Recursive and Follow Links options. The checked Recursive check box causes the node to search the whole folder tree. This, additionaly with the following links, can produece many results.

The resultant list is returned as a JavaScript Array and Result Property specifies where to store it.

FS Stats Node

Use this node when you need to know additional information about a file or folder.

The Path and Filename field say for which file or folder for you want to get details. See path and filename rules in the Common Description section.

You can select All (or All Basic) details or just a single detail with the Attributes dropdown. The All Basic options selects only details directly returned by the Node.js (resp. POSIX) function stat(). The All option provides some extended details, namely: Kind, Mode, Rights and MIME Type.

The Kind gives the following values: file, folder, character (device), block (device), pipe, link, socket. The Mode is an octal expression of file access mode and Rights is the same in textual expression (rwxrwxrwx). The timestamp strings have the ISO 8601 format, e.g. 2021-11-18T17:14:58.000Z.

The MIME Type is only available when mmmagic dependency is installed. This dependecy is large due to MIME Type database, so it is optional. If it is not installed, the item is still in presented, but it returns undefined every time.

When Follow Links is checked, the node will probe a linked target, otherwise the link itself.

You can choose where to put the details with the Result Property dropdown. Result will be an Array for All or All Basic details, or a String or Number for a single detail.

FS Access Node

Use this node when you need to know if your flow has access to a file or folder.

The Path and Filename field say which file or folder you want to test. See path and filename rules in the Common Description section.

The Access checkboxes specify the type of access to test. The Write access means modification of the content of the file. The Read access means reading the content of the file. When both are unchecked, the node will test only if flow can see the existence of file or folder. When a folder is tested, the Read access means to list content and Write access means to create/delete inside.

If a file is accessible according the given criteria, the untouched original message continues to the first output, otherwise to the second output. This node does not produce any error. An error means “unaccessible” and your flow continues on the second output.

Usage Examples

The examples are available in the examples folder. You can import it directly from Node-RED.

License

Node is pulished under MIT License. See LICENSE file.