# File Manager Concepts

For a better understanding of File Manager, you may want to read the following topics.

- TheHierarchicalFileSystemSI

- PathConcepts

- FileOwnershipAndSecuritySI

- DesktopIntro

- MatchingPatterns

- IconBrowser

## Hierarchical File System

If you are new to computers, the idea of a hierarchical file system may also be new to you. This topic describes the basic components of the hierarchical file system.

## What's a File?

1. A file is a container that holds information. Most of the files you use contain information (data) in some particular format&emdash;a document, a spreadsheet, a chart. The format is the particular way the data is arranged inside the file. The format of a file is known as its data type.

   When File Manager is in one of its icon-view modes, you can identify the data type of a file by the icon used to represent the file. Each data type has a different icon.

   Most application programs understand a limited number of data types. For example, a document editor probably cannot read a spreadsheet file. The desktop helps you recognize different types of files using a data type database. A data type identifies the files of a particular format and associates them with the appropriate applications. In most cases, when you double-click on a file, the desktop will automatically launch the application that understands that file's data type.

   The maximum allowable size of a file name varies from system to system. Some operating systems do not allow file names longer than 14 characters. If necessary, consult your system administrator.

## What's a Folder?

1. A folder is a container for files, similar to a folder in a file cabinet. In fact, File Manager uses a folder icon to represent a folder. A folder can contain other folders&emdash; sometimes called subfolders. With folders and subfolders, you can create multiple layers of organization that form a hierarchy. (in other contexts, folders are often referred to as directories.)

   If you drew a picture of the folder hierarchy with each subfolder underneath the folder that contains it&emdash;its parent folder&emdash;and drew a line from each folder to its parent, the picture would look like an upside-down tree. Therefore, we often call the folder hierarchy a folder tree.

   Within any single folder, each file name must have a unique name. However, files in different folders can have the same name.

   As you navigate from folder to folder, your current location is referred to as the current folder.

## What's a Path?

1. The location of a file is often specified by listing the names of the folders and subfolders that lead to the file&emdash;this list is called a path. (See PathConcepts.) A file's path is visible in two places in File Manager. First it is shown in the iconic path as a string of folders. Second, it is shown in text form in the text path line above the view area.

## Paths and Path Names

The path to an object is a way to specify where the object is located in the file system. There are three ways to specify the path: absolute path, relative path, and fully qualified path.

## Absolute Paths

1. A path is an absolute path if it begins at the root folder. The root folder is the highest folder in the hierarchical folder tree. If a path begins with a slash (`/`), it is an absolute path specified from the root folder. For example, the following is an absolute path to the file `letter`:

       /usr/dt/config/letter

## Relative Paths

1. A path is relative if it describes the location of a file or folder as it relates to the current folder. If you are in a folder and you want to move down the folder tree, you don't need to type the full path name. You can just type the path starting with the name of the next folder in the path. If a path does not begin with a slash, it is a relative path. For example, if the current folder is `/usr/dt`, and you want to move to the folder ''/usr/dt/config/letters,'' you would use the following relative path:

       config/letters

   Two special folder names are useful when specifying relative paths. The `.` folder (sometimes called "dot") represents the current folder. The `..` folder (sometimes called "dot-dot") represents the parent folder&emdash;the folder one level up in the folder hierarchy. For example, if your current folder is `/usr/dt/config/panels`, then the relative path to the `sys.dtwmrc` file becomes:

       ../sys.dtwmrc

   because the file is in the `/usr/dt/config` folder, one level above the current folder.

## See Also

1. - ToChangeToAnotherDirectoryTA

   - ToFindAFileByNameTA

   - ToFindAFileByContentsTA

## Object Ownership and Security

Three groups of users can access objects: owner, group, and other. Access is divided into three functions: read permission, write permission, and execute permission.

## Who Has Access?

1. The three basic classes of users are:

   Owner

2. Usually the person who created the file.

Group

- Several users that have been grouped together by the system administrator. For example, the members of a department might belong to the same group.

Other

- All other users on the system.

## What Kind of Access?

1. The access permissions on a file specifies how that file can be accessed by the owner, members of the group, and other users.

   Read Permission

2. Allows access to copy or view the contents of the object.

Write Permission

3. Allows access to change the contents of the object or remove the object.

Execute Permission

4. For a file, allows access to run the file (for executable files, scripts, and actions). For a folder, allows access to run commands, scripts, and actions within that folder.

With File Manager, you can view and change the access permissions for files or folders. See ToChangeAnObjectsOwnerTA and ToChangeAnObjectsPermissionsTA.

## Examples

1. To make a folder private:

   - Change the folder's properties, giving yourself (the owner) read, write, and execute permission, but giving no permissions for group and other. This means that only you and the root user can view the contents of the folder.

   To make an object that you've created available for everyone to use, but protect it so it isn't inadvertently overwritten:

   - Change the file's properties, giving read and execute permission to owner, group, and other. Don't give anyone write permission.

## Default Permissions

1. The default permissions used when you create a new file or folder may be altered by your system administrator. To determine what your current defaults are, create a new file or folder, then Select Change Permissions from the Selected menu to view the default permissions.

## Making Objects More Accessible - Introducing &newline; Workspace Objects

File Manager provides a way to view all the objects in your file system. However, the object is only visible when you are viewing the folder it is in.

To make an object more accessible, you can put it directly on the workspace backdrop. The workspace is that area or surface on which windows appear to lie. (See ToPutAnObjectOnTheDesktopTA.) When an object is placed there, it is called a workspace object.

Placing an object on the workspace does not alter the original file or folder. In fact, the icon that appears on the desktop is really just a shortcut (link) for accessing the real file or folder. Any operation you perform on the workspace object is actually performed on the file or folder it represents.

## Workspace Objects Appear in One Workspace

1. When you place an object on the workspace, it appears only in the current workspace. If you want the object in other workspaces, you must switch to those workspaces and put the object on them.

## Using Workspace Objects

1. You use workspace objects exactly like the objects inside the File Manager or Application Manager windows. To execute an object's default action, double-click its icon on the desktop.

   Each workspace object also has a pop-up menu containing commands and actions for the object. To display the pop-up menu for a workspace object using the mouse, point to the icon, then press and hold mouse button 3. To display the menu through the keyboard, press Alt+Tab until the icon is highlighted, then press Shift+F10.

## Matching Patterns for Finding Files

When you specify a file or folder name, you can include wildcard characters such as asterisk (`*`) and question mark (`?`). The `*` matches any string of zero or more characters, and `?` matches any single character.

## Examples

1. `ba*`

2. Matches all names that begin with the string `ba`

`ba?`

- Matches all three letter names that begin with the string `ba`

`*.vf`

- Matches all names that end with the `.vf` extension

`*.???`

- Matches all names that have a three-character dot extension

The file name and contents can be specified using the same regular expression syntax allowed by the `find` command. (Refer to the `find (1)` man page for more information.)

## Using File Manager as an Icon Browser

Files with names that end in `.pm` or `.bm` contain icon drawings. These are the icons that File Manager uses when it builds icons. By default, you must open these files to see the drawings they contain. If you enable icon browsing, File Manager will make the icon for each file look like whatever drawing is stored inside the file.

To find out how to reconfigure File Manager for icon browsing, see:

- ToEnableIconBrowsingTA

- ToDisableIconBrowsingTA