System folder

Last updated

The System folder is the directory in the classic Mac OS that holds various files required for the system to operate, such as fonts, system extensions, control panels, and preferences.

Contents

System Folder locationmacOS equivalentDescription
Extensions/System/Library/Extensions
/Library/Extensions
Classic Mac: Stores OS extensions (init format)
macOS: Stores kernel extensions and drivers (kext format)
Startup Items/System/Library/StartupItems
/Library/StartupItems
Stores files or scripts to be executed at boot time.
Control Panels/System/Library/PreferencePanes
/Library/PreferencePanes
Classic Mac: Stores system configuration programs, which are loaded at boot time.
macOS: Stores the various properties that appear in System Preferences.
Preferences/Library/PreferencesStores various application and system preferences.

Note: On macOS, files in /Library are not loaded at boot time when booting into Safe Mode.

Location and "blessed" folders


The System Folder is normally located directly below the root directory in the filesystem hierarchy, but does not need to be. The Mac OS identifies the "System Folder" by undocumented characteristics that are independent of its name (it has different names in non-English versions of the Mac OS), or its location in the directory hierarchy. The Macintosh Finder displays this "blessed" folder with a special icon. A "live" System Folder can freely be moved to any location in the directory hierarchy while the OS is operating, and it will continue to operate with no problems after the folder has been moved and after the system is restarted with the folder in its new location.

When the Finder copies a "blessed" folder to a new volume, the copy is "blessed" as well. On a system with more than one disk volume, it is thus easy to create functioning backups of a system simply by dragging the folder. It is also easy to maintain older and newer versions of the OS "in parallel", each on its own volume, and revert to the old one if problems are encountered with the new one.

This degree of flexibility distinguishes the classic Mac OS from most other operating systems, including macOS.

All versions of Mac OS permit multiple copies of the operating system on a single volume. Mac OS 9 added formal support for this by permitting the user to select from multiple copies of the system on the same volume via the Startup Disk control panel, primarily used for selecting which volume to boot from.

Prior to this, one would have to manually bless the copy of the System Folder that they wished to use. A folder can be de-blessed by removing either the System or Finder files from it, which are the two files required for booting. (New World Macintoshes also need the Mac OS ROM file.) Some versions of the classic Mac OS, 8.5 and upwards, check the blessed System Folder before shutdown and warn the user if the System Folder is missing any of the key system files, to prevent them from inadvertently rendering the hard drive unbootable. An alternative to manually blessing the system folders in the Mac OS was to use a utility like System Picker.

Blessing is continued for mactel machines running macOS with an EFI system, albeit in a mostly different manner. See EFI system partition § macOS and the two types of booting for Apple's BootX bootloader. [1]

User accessibility and customization

The System Folder is less protected than the equivalent folders on macOS, in that the contents are all viewable and most files and folders are editable. However it was possible to prevent inexperienced users from accidentally altering the contents by using the Protect System Folder Contents checkbox in the General Controls Control Panel. The Startup and Shut Down programs, Appearance themes, control panels, fonts, and extensions, as well as items in the Apple Menu, are controlled by adding or removing items from folders in the System Folder.

This process was made more convenient when Apple implemented the Extensions Manager , itself a Control Panel that was originally a shareware utility by Ricardo Batista. This allowed activation and deactivation of Control Panels, Extensions, Startup Items and Shutdown Items, and could be invoked fairly early in the boot process by holding down the space bar on the keyboard.

One notable absence was the managements of Fonts. For this, Apple allowed Third-party development of font management programs such as Extensis Suitcase, Adobe Type Manager and AlSoft MasterJuggler.

Related Research Articles

A file manager or file browser is a computer program that provides a user interface to manage files and folders. The most common operations performed on files or groups of files include creating, opening, renaming, copying, moving, deleting and searching for files, as well as modifying file attributes, properties and file permissions. Folders and files may be displayed in a hierarchical tree based on their directory structure.

Hierarchical File System (HFS) is a proprietary file system developed by Apple Inc. for use in computer systems running Mac OS. Originally designed for use on floppy and hard disks, it can also be found on read-only media such as CD-ROMs. HFS is also referred to as Mac OS Standard, while its successor, HFS Plus, is also called Mac OS Extended.

<span class="mw-page-title-main">System 7</span> Seventh major release of the classic Mac OS (1991)

System 7 is the seventh major release of the classic Mac OS operating system for Macintosh computers, made by Apple Computer. It was launched on May 13, 1991, to succeed System 6 with virtual memory, personal file sharing, QuickTime, TrueType fonts, the Force Quit dialog, and an improved user interface.

<span class="mw-page-title-main">Mac OS 8</span> Eighth major release of the classic Mac OS (1997)

Mac OS 8 is the eighth major release of the classic Mac OS operating system for Macintosh computers, released by Apple Computer on July 26, 1997. It includes the largest overhaul of the classic Mac OS experience since the release of System 7, approximately six years before. It places a greater emphasis on color than prior versions. Released over a series of updates, Mac OS 8 represents an incremental integration of many of the technologies which had been developed from 1988 to 1996 for Apple's overly ambitious OS named Copland. Mac OS 8 helped modernize the Mac OS while Apple developed its next-generation operating system, Mac OS X.

Macintosh File System (MFS) is a volume format created by Apple Computer for storing files on 400K floppy disks. MFS was introduced with the original Apple Macintosh computer in January 1984.

On the classic Mac OS, extensions were small pieces of code that extended the system's functionality. They were run initially at start-up time, and operated by a variety of mechanisms, including trap patching and other code modifying techniques. Initially an Apple developer hack, extensions became the standard way to provide a modular operating system. Large amounts of important system services such as the TCP/IP network stacks and USB and FireWire support were optional components implemented as extensions. The phrase "system extension" later came to encompass faceless background applications as well.

launchd is an init and operating system service management daemon created by Apple Inc. as part of macOS to replace its BSD-style init and SystemStarter. There have been efforts to port launchd to FreeBSD and derived systems.

Extension conflicts were sometimes a common nuisance on Apple Macintosh computers running the classic Mac OS, especially System 7. Extensions were bundles of code that extended the operating system's capabilities by directly patching OS calls, thus receiving control instead of the operating system when applications made system calls. Generally, once an extension completed its task, it was supposed to pass on the system call to the operating system's routine. If multiple extensions want to patch the same system call, they end up receiving the call in a chain, the first extension in line passing it on to the next, and so on in the order they are loaded, until the last extension passes to the operating system. If an extension does not hand the next extension in line what it is expecting, problems occur; ranging from unexpected behavior to full system crashes. This is triggered by several factors such as carelessly programmed and malicious extensions that change or disrupt the way part of the system software works.

In NeXTSTEP, OPENSTEP, and their lineal descendants macOS, iOS, iPadOS, tvOS, and watchOS, and in GNUstep, a bundle is a file directory with a defined structure and file extension, allowing related files to be grouped together as a conceptually single item.

<span class="mw-page-title-main">Apple–Intel architecture</span> Unofficial name used for Macintosh models that use Intel x86 processors

The Apple–Intel architecture, or Mactel, is an unofficial name used for Macintosh personal computers developed and manufactured by Apple Inc. that use Intel x86 processors, rather than the PowerPC and Motorola 68000 ("68k") series processors used in their predecessors or the ARM-based Apple silicon SoCs used in their successors. As Apple changed the architecture of its products, they changed the firmware from the Open Firmware used on PowerPC-based Macs to the Intel-designed Extensible Firmware Interface (EFI). With the change in processor architecture to x86, Macs gained the ability to boot into x86-native operating systems, while Intel VT-x brought near-native virtualization with macOS as the host OS.

In the macOS operating system, .DS_Store is a file that stores custom attributes of its containing folder, such as folder view options, icon positions, and other visual information. The name is an abbreviation of Desktop Services Store, reflecting its purpose. It is created and maintained by the Finder application in every folder, and has functions similar to the file desktop.ini in Microsoft Windows. Starting with a period . character, it is hidden in Finder and many Unix utilities. Its internal structure is proprietary, but has been reverse-engineered. Starting at macOS 10.12 16A238m, Finder will not display .DS_Store files.

<span class="mw-page-title-main">EFI system partition</span> Partition used by Unified Extensible Firmware Interface

The EFIsystem partition or ESP is a partition on a data storage device that is used by computers that have the Unified Extensible Firmware Interface (UEFI). When a computer is booted, UEFI firmware loads files stored on the ESP to start operating systems and various utilities.

<span class="mw-page-title-main">Time Machine (macOS)</span> Backup software application developed by Apple and distributed as part of macOS

Time Machine is the backup mechanism of macOS, the desktop operating system developed by Apple. The software is designed to work with both local storage devices and network-attached disks, and is commonly used with external disk drives connected using either USB or Thunderbolt. It was first introduced in Mac OS X 10.5 Leopard, which was released in October 2007 and incrementally refined in subsequent releases of macOS. Time Machine was revamped in macOS 11 Big Sur to support APFS, thereby enabling "faster, more compact, and more reliable backups" than were possible previously.

<span class="mw-page-title-main">Apple menu</span> System menu on Mac operating systems

The Apple menu is a drop-down menu that is on the left side of the menu bar in the classic Mac OS, macOS and A/UX operating systems. The Apple menu's role has changed throughout the history of Apple Inc.'s operating systems, but the menu has always featured a version of the Apple logo.

<span class="mw-page-title-main">Trash (computing)</span> Temporary storage for deleted files

In computing, the trash, also known by other names such as dustbin, wastebasket, and others, is a graphical user interface desktop metaphor for temporary storage for files set aside by the user for deletion, but not yet permanently erased. The concept and name is part of Mac operating systems, a similar implementation is called the Recycle Bin in Microsoft Windows, and other operating systems use other names.

<span class="mw-page-title-main">BootX (Apple)</span> Boot loader developed by Apple Inc.

BootX is a software-based bootloader designed and developed by Apple Inc. for use on the company's Macintosh computer range. BootX is used to prepare the computer for use, by loading all required device drivers and then starting-up Mac OS X by booting the kernel on all PowerPC Macintoshes running the Mac OS X 10.2 operating system or later versions.

<span class="mw-page-title-main">System 1</span> First major release of classic Apple Macintosh operating system (1984)

The Macintosh "System 1" is the first major release of the classic Mac OS operating system. It was developed for the Motorola 68000 microprocessor. System 1 was released on January 24, 1984, along with the Macintosh 128K, the first in the Macintosh family of personal computers. It received one update, "System 1.1" on December 29, 1984, before being succeeded by System 2.

<span class="mw-page-title-main">Apple Disk Image</span> File format developed by Apple and used by macOS

AppleDisk Image is a disk image format commonly used by the macOS operating system. When opened, an Apple Disk Image is mounted as a volume within the Finder.

<span class="mw-page-title-main">Classic Mac OS</span> Original operating system of Apple Mac (1984–2001)

Mac OS is the series of operating systems developed for the Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and ending with Mac OS 9. The Macintosh operating system is credited with having popularized the graphical user interface concept. It was included with every Macintosh that was sold during the era in which it was developed, and many updates to the system software were done in conjunction with the introduction of new Macintosh systems.

References

  1. "apple-opensource/bless". GitHub. Retrieved 6 January 2020.