2d4f3e2ac9
The layer is now redundant, since everything left in "pkgs" is in the "racket-pkgs" category.
48 lines
2.1 KiB
Racket
48 lines
2.1 KiB
Racket
#lang scribble/doc
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@(require scribble/bnf "mz.rkt")
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@title[#:tag "unixpaths"]{@|AllUnix| Paths}
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In a path on @|AllUnix|, a @litchar{/} separates elements of the path,
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@litchar{.} as a path element always means the directory indicated by
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preceding path, and @litchar{..} as a path element always means the
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parent of the directory indicated by the preceding path. A leading
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@litchar{~} in a path is not treated specially, but
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@racket[expand-user-path] can be used to convert a leading @litchar{~}
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element to a user-specific directory. No other character or byte has a
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special meaning within a path. Multiple adjacent @litchar{/} are
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equivalent to a single @litchar{/} (i.e., they act as a single path
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separator).
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A path root is always @litchar{/}. A path starting with @litchar{/} is
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an absolute, complete path, and a path starting with any other
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character is a relative path.
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Any pathname that ends with a @litchar{/} syntactically refers to a
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directory, as does any path whose last element is @litchar{.} or
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@litchar{..}.
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A @|AllUnix| path is @techlink{cleanse}d by replacing multiple adjacent
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@litchar{/}s with a single @litchar{/}.
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For @racket[(bytes->path-element _bstr)], @racket[bstr] must not
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contain any @litchar{/}, otherwise the @exnraise[exn:fail:contract].
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The result of @racket[(path-element->bytes _path)] or
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@racket[(path-element->string _path)] is always the same as the result
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of @racket[(path->bytes _path)] and @racket[(path->string
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_path)]. Since that is not the case for other platforms, however,
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@racket[path-element->bytes] and @racket[path-element->string] should
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be used when converting individual path elements.
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On Mac OS X, Finder aliases are zero-length files.
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@section[#:tag "unixpathrep"]{Unix Path Representation}
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A path on @|AllUnix| is natively a byte string. For presentation to
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users and for other string-based operations, a path is converted
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to/from a string using the current locale's encoding with @litchar{?}
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(encoding) or @code{#\uFFFD} (decoding) in place of errors. Beware
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that the encoding may not accommodate all possible paths as
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distinct strings.
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