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10.1 Format of ".plt" Archives
10.2 API for Packing
pack-collections-plt
pack-collections
pack-plt
pack
std-filter
mztar

10 raco pack: Packing Library Collections

The raco pack command creates an archive of files and directories. Formerly, such archives were used directly to distribute library files to Racket users, but the package manager (see Package Management in Racket) is now the preferred mechanism for distribution.

A packed archive usually has the suffix ".plt". The raco pkg command recognizes a ".plt" archive for installation as a package. The raco setup command (see raco setup: Installation Management) also supports ".plt" unpacking and installation when using the -A flag, but such installations do not benefit from the more general management facilities of raco pkg, while the raco unpack command (see raco unpack: Unpacking Library Collections) unpacks an archive locally without attempting to install it. DrRacket recognizes the ".plt" and currently treats such an archive in the same way as raco setup -A.

An archive contains the following elements:

Specify individual directories and files for the archive when not using --collect. Each file and directory must be specified with a relative path. By default, if the archive is unpacked with DrRacket, the user will be prompted for a target directory, and if raco setup is used to unpack the archive, the files and directories will be unpacked relative to the current directory. If the --at-plt flag is provided, the files and directories will be unpacked relative to the user’s Racket add-ons directory, instead. Finally, if the --all-users flag is provided, the files and directories will be unpacked relative to the Racket installation directory, instead.

Use the --collect flag to pack one or more collections; sub-collections can be designated by using a / as a path separator on all platforms. In this mode, raco pack automatically uses paths relative to the Racket installation or add-ons directory for the archived files, and the collections will be set-up after unpacking. In addition, raco pack consults each collection’s "info.rkt" file, as described below, to determine the set of required and conflicting collections. Finally, raco pack consults the first collection’s "info.rkt" file to obtain a default name for the archive. For example, the following command creates a "sirmail.plt" archive for distributing a "sirmail" collection:

  raco pack --collect sirmail.plt sirmail

When packing collections, raco pack checks the following fields of each collection’s "info.rkt" file (see "info.rkt" File Format):

For example, the "info.rkt" file in the "sirmail" collection might contain the following info declaration:

#lang info
(define name "SirMail")
(define mred-launcher-libraries (list "sirmail.rkt"))
(define mred-launcher-names (list "SirMail"))
(define requires (list (list "mred")))

Then, the "sirmail.plt" file (created by the command-line example above) will contain the name “SirMail.” When the archive is unpacked, the unpacker will check that the "mred" collection is installed, and that "mred" has the same version as when "sirmail.plt" was created.

10.1 Format of ".plt" Archives

The extension ".plt" is not required for a distribution archive, but the ".plt"-extension convention helps users identify the purpose of a distribution file.

The raw format of a distribution file is described below. This format is uncompressed and sensitive to communication modes (text vs. binary), so the distribution format is derived from the raw format by first compressing the file using gzip, then encoding the gzipped file with the MIME base64 standard (which relies only the characters A-Z, a-z, 0-9, +, /, and =; all other characters are ignored when a base64-encoded file is decoded).

The raw format is

The archive continues with unpackables. Unpackables are extracted until the end-of-file is found (as indicated by an = in the base64-encoded input archive).

An unpackable is one of the following:

10.2 API for Packing

 (require setup/pack) package: base
Although the raco pack command can be used to create most ".plt" files, the setup/pack library provides a more general API for making ".plt" archives.

procedure

(pack-collections-plt 
  dest 
  name 
  collections 
  [#:replace? replace? 
  #:at-plt-home? at-home? 
  #:test-plt-collects? test? 
  #:extra-setup-collections collection-list 
  #:file-filter filter-proc]) 
  void?
  dest : path-string?
  name : string?
  collections : (listof (listof path-string?))
  replace? : boolean? = #f
  at-home? : boolean? = #f
  test? : boolean? = #t
  collection-list : (listof path-string?) = null
  filter-proc : (path-string? . -> . boolean?) = std-filter
Creates the ".plt" file specified by the pathname dest, using the name as the name reported to raco setup as the archive’s description.

The archive contains the collections listed in collections, which should be a list of collection paths; each collection path is, in turn, a list of relative-path strings.

If the #:replace? argument is #f, then attempting to unpack the archive will report an error when any of the collections exist already, otherwise unpacking the archive will overwrite an existing collection.

If the #:at-plt-home? argument is #t, then the archived collections will be installed into the Racket installation directory instead of the user’s directory if the main "collects" directory is writable by the user. If the #:test-plt-collects? argument is #f (the default is #t) and the #:at-plt-home? argument is #t, then installation fails if the main "collects" directory is not writable.

The optional #:extra-setup-collections argument is a list of collection paths that are not included in the archive, but are set-up when the archive is unpacked.

The optional #:file-filter argument is the same as for pack-plt.

procedure

(pack-collections dest    
  name    
  collections    
  replace?    
  extra-setup-collections    
  [filter    
  at-plt-home?])  void?
  dest : path-string?
  name : string?
  collections : (listof (listof path-string?))
  replace? : boolean?
  extra-setup-collections : (listof path-string?)
  filter : (path-string? . -> . boolean?) = std-filter
  at-plt-home? : boolean? = #f
Old, keywordless variant of pack-collections-plt for backward compatibility.

procedure

(pack-plt dest    
  name    
  paths    
  [#:as-paths as-paths    
  #:file-filter filter-proc    
  #:encode? encode?    
  #:file-mode file-mode-sym    
  #:unpack-unit unpack-spec    
  #:collections collection-list    
  #:plt-relative? plt-relative?    
  #:at-plt-home? at-plt-home?    
  #:test-plt-dirs dirs    
  #:requires mod-and-version-list    
  #:conflicts mod-list])  void?
  dest : path-string?
  name : string?
  paths : (listof path-string?)
  as-paths : (listof path-string?) = paths
  filter-proc : (path-string? . -> . boolean?) = std-filter
  encode? : boolean? = #t
  file-mode-sym : symbol? = 'file
  unpack-spec : any/c = #f
  collection-list : (listof path-string?) = null
  plt-relative? : any/c = #f
  at-plt-home? : any/c = #f
  dirs : (or/c (listof path-string?) false/c) = #f
  mod-and-version-list : 
(listof (listof path-string?)
        (listof exact-integer?))
 = null
  mod-list : (listof (listof path-string?)) = null
Creates the ".plt" file specified by the pathname dest, using the string name as the name reported to raco setup as the archive’s description. The paths argument must be a list of relative paths for directories and files; the contents of these files and directories will be packed into the archive. The optional as-paths list provides the path to be recorded in the archive for each element of paths (so that the unpacked paths can be different from the packed paths).

The #:file-filter procedure is called with the relative path of each candidate for packing. If it returns #f for some path, then that file or directory is omitted from the archive. If it returns 'file or 'file-replace for a file, the file is packed with that mode, rather than the default mode. The default is std-filter.

If the #:encode? argument is #f, then the output archive is in raw form, and still must be gzipped and mime-encoded (in that order). The default value is #t.

The #:file-mode argument must be 'file or 'file-replace, indicating the default mode for a file in the archive. The default is 'file.

The #:unpack-unit argument is usually #f. Otherwise, it must be an S-expression for the S-expression that describes unpacking; see Format of ".plt" Archives more information about the unit. If the #:unpack-unit argument is #f, an appropriate S-expression is generated.

The #:collections argument is a list of collection paths to be compiled after the archive is unpacked. The default is the null.

If the #:plt-relative? argument is true (the default is #f), the archive’s files and directories are to be unpacked relative to the user’s add-ons directory or the Racket installation directories, depending on whether the #:at-plt-home? argument is true and whether directories specified by #:test-plt-dirs are writable by the user.

If the #:at-plt-home? argument is true (the default is #f), then #:plt-relative? must be true, and the archive is unpacked relative to the Racket installation directory. In that case, a relative path that starts with "collects" is mapped to the installation’s main "collects" directory, and so on, for the following the initial directory names:

If #:test-plt-dirs is a list, then #:at-plt-home? must be #t. In that case, when the archive is unpacked, if any of the relative directories in the #:test-plt-dirs list is unwritable by the current user, then the archive is unpacked in the user’s add-ons directory after all.

The #:requires argument should have the shape (list (list coll-path version) ...) where each coll-path is a non-empty list of relative-path strings, and each version is a (possibly empty) list of exact integers. The indicated collections must be installed at unpacking time, with version sequences that match as much of the version sequence specified in the corresponding version. A collection’s version is indicated by the version field of its "info.rkt" file.

The #:conflicts argument should have the shape (list coll-path ...) where each coll-path is a non-empty list of relative-path strings. The indicated collections must not be installed at unpacking time.

procedure

(pack dest    
  name    
  paths    
  collections    
  [filter    
  encode?    
  file-mode    
  unpack-unit    
  plt-relative?    
  requires    
  conflicts    
  at-plt-home?])  void?
  dest : path-string?
  name : string?
  paths : (listof path-string?)
  collections : (listof path-string?)
  filter : (path-string? . -> . boolean?) = std-filter
  encode? : boolean? = #t
  file-mode : symbol? = 'file
  unpack-unit : any/c = #f
  plt-relative? : boolean? = #t
  requires : 
(listof (listof path-string?)
        (listof exact-integer?))
 = null
  conflicts : (listof (listof path-string?)) = null
  at-plt-home? : boolean? = #f
Old, keywordless variant of pack-plt for backward compatibility.

procedure

(std-filter p)  boolean?

  p : path-string?
Returns #t unless p, after stripping its directory path and converting to a byte string, matches one of the following regular expressions: ^[.]git, ^[.]svn$, ^CVS$, ^[.]cvsignore, ^compiled$, ^doc, ~$, ^#.*#$, ^[.]#, or [.]plt$.

procedure

(mztar path    
  [#:as-path as-path]    
  output    
  filter    
  file-mode)  void?
  path : path-string?
  as-path : path-string? = path
  output : output-port?
  filter : (path-string? . -> . boolean?)
  file-mode : (symbols 'file 'file-replace)
Called by pack to write one directory/file path to the output port output using the filter procedure filter (see pack for a description of filter). The path is recorded in the output as as-path, in case the unpacked path should be different from the original path. The file-mode argument specifies the default mode for packing a file, either 'file or 'file-replace.