65 lines
2.5 KiB
Racket
65 lines
2.5 KiB
Racket
#lang scribble/doc
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@(require "common.ss"
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(for-label file/gunzip
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file/gzip))
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@title[#:tag "gunzip"]{@exec{gzip} Decompression}
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@defmodule[file/gunzip]{The @schememodname[file/gunzip] library provides
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utilities to decompress archive files in @exec{gzip} format, or simply
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to deccompress data using the @exec{pkzip} ``inflate'' method.}
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@defproc[(gunzip [file path-string?]
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[output-name-filter (string? boolean? . -> . path-string?)
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(lambda (file archive-supplied?) file)])
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void?]{
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Extracts data that was compressed using the @exec{gzip} utility (or
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@scheme[gzip] function), writing the uncompressed data directly to a
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file. The @scheme[file] argument is the name of the file containing
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compressed data. The default output file name is the original name of
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the compressed file as stored in @scheme[file]. If a file by this name
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exists, it will be overwritten. If no original name is stored in the
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source file, @scheme["unzipped"] is used as the default output file
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name.
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The @scheme[output-name-filter] procedure is applied to two
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arguments---the default destination file name and a boolean that is
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@scheme[#t] if this name was read from @scheme[file]---before the
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destination file is created. The return value of the file is used as
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the actual destination file name (to be opened with the
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@scheme['truncate] flag of @scheme[open-output-file]).
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If the compressed data turns out to be corrupted, the
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@scheme[exn:fail] exception is raised.}
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@defproc[(gunzip-through-ports [in input-port?]
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[out output-port?])
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void?]{
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Reads the port @scheme[in] for compressed data that was created using
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the @exec{gzip} utility, writing the uncompressed data to the port
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@scheme[out].
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If the compressed data turns out to be corrupted, the
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@scheme[exn:fail] exception is raised. The unzipping process may peek
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further into @scheme[in] than needed to decompress the data, but it
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will not consume the unneeded bytes.}
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@defproc[(inflate [in input-port?]
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[out output-port?])
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void?]{
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Reads @exec{pkzip}-format ``deflated'' data from the port @scheme[in]
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and writes the uncompressed (``inflated'') data to the port
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@scheme[out]. The data in a file created by @exec{gzip} uses this
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format (preceded with some header information).
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If the compressed data turns out to be corrupted, the
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@scheme[exn:fail] exception is raised. The inflate process may peek
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further into @scheme[in] than needed to decompress the data, but it
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will not consume the unneeded bytes.}
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