macOS Structure

macOS Structure#

Root directory layout the operator needs when traversing a live macOS host or a mounted disk image. The hidden .-prefixed entries are Apple-specific.

References#

Hidden Apple entries#

Entry

Description

/

Root, parent of every other file.

.DS_Store

Finder settings (icon location, background, window size, file names) in every directory the Finder visits. Similar to desktop.ini on Windows.

.DocumentRevisions-V100/

Internal version control system (TextEdit, KeyNote, Pages, Numbers). Stores a copy of each file every save.

.fseventsd/

File-system events daemon process writing event logs and handling change notifications for userspace.

.HFS+ Private Directory Data?/

HFS+ private directories used for hard-linked folders and files. macOS leans on hard links UNIX needs but HFS+ does not natively support.

.PKInstallSandboxManager/

Software updates and the install sandbox.

.PKInstallSandboxManager-SystemSoftware/

System software updates.

.Spotlight-V100/

Spotlight index data for searches.

.Trashes/

Trash. On a boot volume, files live in ~/.Trash. On other volumes, /.Trashes/$UID/.

.vol/

Pseudo-directory to access files by ID or inode. Maps HFS+ file IDs to files.

Top-level directories#

Directory

Description

/Applications/

All Mac OS X applications.

/bin/

Essential common binaries needed to boot the OS.

/cores/

Symlink to /private/cores. Where core dumps land (core.pid).

/dev/

Device files (keyboards, mice, trackpads).

/etc/

Symlink to /private/etc. Local system configuration.

/home/

All user files. Every user has a home directory.

/Library/

Shared libraries, settings, preferences. The per-user counterpart lives under ~/Library.

/net/

Common default automounter local path (/net/hostname/nfspath).

/Network/

Attach point for network-wide resources and server volumes.

/opt/

Optional installs such as X11.

/private/

Where Unix tmp, var, etc, and cores live.

/sbin/

System administration and configuration executables.

/System/

System files, libraries, preferences (critical for proper function).

/tmp/

Symlink to /private/tmp. World-writable temporary storage.

/Users/

All user accounts and their files / settings.

/usr/

BSD Unix applications and support files.

/var/

Symlink to /private/var. Logs, configuration, frequently modified data.

/vm/

Swap files and contents of RAM for sleep.

/Volumes/

Mounted devices and volumes (hard disks, CD/DVD, DMG, boot volume).
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