# File System

These global variables provide information about file types, file handling, and file operations in the OSL environment.

## File Type Definitions

The `file_types` object contains definitions for various file types recognized by the system. Each entry includes:

* Icon definition (for visual representation)
* Description of the file type
* Associated applications that can open the file type

Here's a summary of some key file types defined in the system:

| File Extension                           | Description      | Associated Applications         |
| ---------------------------------------- | ---------------- | ------------------------------- |
| `.folder`                                | Directory/Folder | Files.osl                       |
| `.osl`                                   | Origin Script    | Process\_Opener.osl, Studio.osl |
| `.orsl`                                  | Origin Script    | Process\_Opener.osl, Studio.osl |
| `.txt`                                   | Plain Text       | Studio.osl                      |
| `.md`                                    | Markdown         | Studio.osl                      |
| `.json`                                  | JSON File        | Studio.osl                      |
| `.xml`                                   | Markup           | Studio.osl                      |
| `.js`                                    | Javascript       | Studio.osl                      |
| `.html`                                  | HTML File        | Studio.osl                      |
| `.css`                                   | CSS File         | Studio.osl                      |
| `.py`                                    | Python           | Studio.osl                      |
| `.png`, `.jpg`, `.jpeg`, `.webp`, `.bmp` | Image Files      | Previewer.osl                   |
| `.mp4`, `.webm`                          | Video Files      | Media\_Player.osl               |
| `.mp3`, `.wav`, `.flac`                  | Audio Files      | Media\_Player.osl               |

## File Constants and Special Values

| Variable   | Type   | Description                              |
| ---------- | ------ | ---------------------------------------- |
| `null`     | Null   | Special value representing null or empty |
| `newline`  | String | String representing a newline character  |
| `infinity` | Number | Special value representing infinity      |

## Examples

```javascript
// Check if a file extension is recognized
def isRecognizedFileType(filename) (
  local extension = filename.split(".").last()
  return file_types[extension] != null
)

// Get the description of a file type
def getFileTypeDescription(filename) (
  local extension = filename.split(".").last()
  local fileType = file_types[extension]
  
  if fileType (
    return fileType[2]
    // Return the description (second element)
  ) else (
    return "Unknown file type"
  )
)

// Get applications that can open a file
def getCompatibleApps(filename) (
  local extension = filename.split(".").last()
  local fileType = file_types[extension]
  
  if fileType and fileType[3] (
    return fileType[3]
    // Return the array of applications
  ) else (
    return []
  )
)

// Example usage
filename = "document.txt"

if isRecognizedFileType(filename) (
  log "File type: " ++ getFileTypeDescription(filename)
  
  apps = getCompatibleApps(filename)
  if apps.len > 0 (
    log "Can be opened with: " ++ apps.join(", ")
  ) else (
    log "No compatible applications found"
  )
)
```

## Notes

* The file types configuration is used by the system to determine how to display and handle different file types.
* New file types can be registered by applications by extending the `file_types` object.
* The icon definition uses a custom drawing syntax to define how the file type's icon should appear.
* Applications associated with file types are paths to OSL script files that can handle the specified file type.