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Also do a better JSON and testing for deep and shallow NAR listings. As documented, this for file system objects themselves, since `MemorySourceAccessor` is an implementation detail.
68 lines
1.8 KiB
Markdown
68 lines
1.8 KiB
Markdown
# File System Object
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Nix uses a simplified model of the file system, which consists of file system objects.
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Every file system object is one of the following:
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- [**Regular File**]{#regular}
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- A possibly empty sequence of bytes for contents
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- A single boolean representing the [executable](https://en.m.wikipedia.org/wiki/File-system_permissions#Permissions) permission
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- [**Directory**]{#directory}
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Mapping of names to child file system objects
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- [**Symbolic link**]{#symlink}
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An arbitrary string, known as the *target* of the symlink.
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In general, Nix does not assign any semantics to symbolic links.
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Certain operations however, may make additional assumptions and attempt to use the target to find another file system object.
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> See [the Wikpedia article on symbolic links](https://en.m.wikipedia.org/wiki/Symbolic_link) for background information if you are unfamiliar with this Unix concept.
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File system objects and their children form a tree.
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A bare file or symlink can be a root file system object.
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Nix does not encode any other file system notions such as [hard links](https://en.m.wikipedia.org/wiki/Hard_link), [permissions](https://en.m.wikipedia.org/wiki/File-system_permissions), timestamps, or other metadata.
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## Examples of file system objects
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A plain file:
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```
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50 B, executable: false
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```
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An executable file:
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```
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122 KB, executable: true
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```
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A symlink:
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```
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-> /usr/bin/sh
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```
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A directory with contents:
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```
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├── bin
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│ └── hello: 35 KB, executable: true
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└── share
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├── info
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│ └── hello.info: 36 KB, executable: false
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└── man
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└── man1
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└── hello.1.gz: 790 B, executable: false
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```
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A directory that contains a symlink and other directories:
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```
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├── bin -> share/go/bin
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├── nix-support/
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└── share/
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```
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