Archive Module

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This XQuery Module contains functions to handle archives (including ePub, Open Office, JAR, and many other formats). New ZIP and GZIP archives can be created, existing archives can be updated, and the archive entries can be listed and extracted. The archive:extract-binary function includes an example for writing the contents of an archive to disk.

Contents

[edit] Conventions

All functions in this module are assigned to the http://basex.org/modules/archive namespace, which is statically bound to the archive prefix.
All errors are assigned to the http://basex.org/errors namespace, which is statically bound to the bxerr prefix.

[edit] Functions

[edit] archive:create

Signatures archive:create($entries as item(), $contents as item()*) as xs:base64Binary
archive:create($entries as item(), $contents as item()*, $options as map(xs:string, xs:string)) as xs:base64Binary
Summary Creates a new archive from the specified entries and contents.
The $entries argument contains meta information required to create new entries. All items may either be of type xs:string, representing the entry name, or element(archive:entry), containing the name as text node and additional, optional attributes:
  • last-modified: timestamp, specified as xs:dateTime (default: current time)
  • compression-level: 0-9, 0 = uncompressed (default: 8)
  • encoding: for textual entries (default: UTF-8)

An example:

<archive:entry last-modified='2011-11-11T11:11:11'
               compression-level='8'
               encoding='US-ASCII'>hello.txt</archive:entry>

The actual $contents must be xs:string or xs:base64Binary items.
The $options parameter contains archiving options:

  • format: allowed values are zip and gzip. zip is the default.
  • algorithm: allowed values are deflate and stored (for the zip format). deflate is the default.
Errors ARCH0001: the number of entries and contents differs.
ARCH0002: the specified option or its value is invalid or not supported.
ARCH0003: entry descriptors contain invalid entry names, timestamps or compression levels.
ARCH0004: the specified encoding is invalid or not supported, or the string conversion failed. Invalid XML characters will be ignored if the CHECKSTRINGS option is turned off.
ARCH0005: the chosen archive format only allows single entries.
ARCH9999: archive creation failed for some other reason.
Examples The following one-liner creates an archive archive.zip with one file file.txt:
archive:create(<archive:entry>file.txt</archive:entry>, 'Hello World')

The following function creates an archive mp3.zip, which contains all MP3 files of a local directory:

let $path  := 'audio/'
let $files := file:list($path, true(), '*.mp3')
let $zip   := archive:create(
  $files ! element archive:entry { . },
  $files ! file:read-binary($path || .))
return file:write-binary('mp3.zip', $zip)

[edit] archive:create-from

Signatures archive:create-from($path as xs:string) as xs:base64Binary
archive:create-from($path as xs:string, $options as map(xs:string, xs:string)) as xs:base64Binary
archive:create-from($path as xs:string, $options as map(xs:string, xs:string), $entries as item()*) as xs:base64Binary
Summary This convenience function creates an archive from all files in the specified directory $path.
The $options parameter contains archiving options, and the files to be archived can be limited via $entries. The format of the two last arguments is the same as for archive:create.
Errors no-dir: the specified path does not point to a directory.
is-dir: one of the specified entries points to a directory.
not-found: a specified entry does not exist.
ARCH9999: archive creation failed for some other reason.
Examples This example writes the files of a user’s home directory to archive.zip:
let $zip := archive:create-from('/home/user/')
return file:write-binary('archive.zip', $zip)

[edit] archive:entries

Signatures archive:entries($archive as xs:base64Binary) as element(archive:entry)*
Summary Returns the entry descriptors of the specified $archive. A descriptor contains the following attributes, provided that they are available in the archive format:
  • size: original file size
  • last-modified: timestamp, formatted as xs:dateTime
  • compressed-size: compressed file size

An example:

<archive:entry size="1840" last-modified="2009-03-20T03:30:32" compressed-size="672">
  doc/index.html
</archive:entry>
Errors ARCH9999: archive creation failed for some other reason.
Examples Sums up the file sizes of all entries of a JAR file:
sum(archive:entries(file:read-binary('zip.zip'))/@size)

[edit] archive:options

Signatures archive:options($archive as xs:base64Binary) as map(xs:string, xs:string)
Summary Returns the options of the specified $archive in the format specified by archive:create.
Errors ARCH0002: The packing format is not supported.
ARCH9999: archive creation failed for some other reason.
Examples A standard ZIP archive will return the following options:
map {
  "format": "zip",
  "algorithm": "deflate"
}

[edit] archive:extract-text

Signatures archive:extract-text($archive as xs:base64Binary) as xs:string*
archive:extract-text($archive as xs:base64Binary, $entries as item()*) as xs:string*
archive:extract-text($archive as xs:base64Binary, $entries as item()*, $encoding as xs:string) as xs:string*
Summary Extracts entries of the specified $archive and returns them as texts.
The returned entries can be limited via $entries. The format of the argument is the same as for archive:create (attributes will be ignored).
The encoding of the input files can be specified via $encoding.
Errors ARCH0004: the specified encoding is invalid or not supported, or the string conversion failed. Invalid XML characters will be ignored if the CHECKSTRINGS option is turned off.
ARCH9999: archive creation failed for some other reason.
Examples The following expression extracts all .txt files from an archive:
let $archive := file:read-binary("documents.zip")
for $entry in archive:entries($archive)[ends-with(., '.txt')]
return archive:extract-text($archive, $entry)

[edit] archive:extract-binary

Signatures archive:extract-binary($archive as xs:base64Binary) as xs:base64Binary*
archive:extract-binary($archive as xs:base64Binary, $entries as item()*) as xs:base64Binary*
Summary Extracts entries of the specified $archive and returns them as binaries.
The returned entries can be limited via $entries. The format of the argument is the same as for archive:create (attributes will be ignored).
Errors ARCH9999: archive creation failed for some other reason.
Examples This example unzips all files of an archive to the current directory:
let $archive  := file:read-binary('archive.zip')
let $entries  := archive:entries($archive)
let $contents := archive:extract-binary($archive)
return for-each-pair($entries, $contents, function($entry, $content) {
  file:create-dir(replace($entry, "[^/]+$", "")),
  file:write-binary($entry, $content)
})

[edit] archive:extract-to

Signatures archive:extract-to($path as xs:string, $archive as xs:base64Binary) as empty-sequence()
archive:extract-to($path as xs:string, $archive as xs:base64Binary, $entries as item()*) as empty-sequence()
Summary This convenience function writes files of an $archive directly to the specified directory $path.
The archive entries to be written can be restricted via $entries. The format of the argument is the same as for archive:create (attributes will be ignored).
Errors ARCH9999: archive creation failed for some other reason.
Examples The following expression unzips all files of an archive to the current directory:
archive:extract-to('.', file:read-binary('archive.zip'))

[edit] archive:update

Signatures archive:update($archive as xs:base64Binary, $entries as item()*, $contents as item()*) as xs:base64Binary
Summary Creates an updated version of the specified $archive with new or replaced entries.
The format of $entries and $contents is the same as for archive:create.
Errors ARCH0001: the number of entries and contents differs.
ARCH0003: entry descriptors contain invalid entry names, timestamps, compression levels or encodings.
ARCH0004: the specified encoding is invalid or not supported, or the string conversion failed. Invalid XML characters will be ignored if the CHECKSTRINGS option is turned off.
ARCH0005: the entries of the given archive cannot be modified.
ARCH9999: archive creation failed for some other reason.
Examples This example replaces texts in a Word document:
declare variable $input  := "HelloWorld.docx";
declare variable $output := "HelloUniverse.docx";
declare variable $doc    := "word/document.xml";
 
let $archive := file:read-binary($input)
let $entry   :=
  copy $c := fn:parse-xml(archive:extract-text($archive, $doc))
  modify replace value of node $c//*[text() = "HELLO WORLD!"] with "HELLO UNIVERSE!"
  return fn:serialize($c)
let $updated := archive:update($archive, $doc, $entry)
return file:write-binary($output, $updated)

[edit] archive:delete

Signatures archive:delete($archive as xs:base64Binary, $entries as item()*) as xs:base64Binary
Summary Deletes entries from an $archive.
The format of $entries is the same as for archive:create.
Errors ARCH0005: the entries of the given archive cannot be modified.
ARCH9999: archive creation failed for some other reason.
Examples This example deletes all HTML files in an archive and creates a new file:
let $zip := file:read-binary('old.zip')
let $entries := archive:entries($zip)[matches(., '\.x?html?$', 'i')]
return file:write-binary('new.zip', archive:delete($zip, $entries))

[edit] Errors

Code Description
ARCH0001 The number of specified entries and contents differs.
ARCH0002 The packing format or the specified option is invalid or not supported.
ARCH0003 Entry descriptors contain invalid entry names, timestamps or compression levels.
ARCH0004 The specified encoding is invalid or not supported, or the string conversion failed. Invalid XML characters will be ignored if the CHECKSTRINGS option is turned off.
ARCH0005 The entries of the given archive cannot be modified.
ARCH0006 The chosen archive format only allows single entries.
ARCH9999 Archive processing failed for some other reason.

[edit] Changelog

Version 8.5
Version 8.3
Version 7.7

The module was introduced with Version 7.3.

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