7 tar File Extraction
| (require file/untar) | package: base |
procedure
(untar in [ #:dest dest-path #:strip-count strip-count #:permissive? permissive? #:filter filter-proc #:handle-entry handle-entry]) → void? in : (or/c path-string? input-port?) dest-path : (or/c path-string? #f) = #f strip-count : exact-nonnegative-integer? = 0 permissive? : any/c = #f
filter-proc :
(path? (or/c path? #f) symbol? exact-integer? (or/c path? #f) exact-nonnegative-integer? exact-nonnegative-integer? . -> . any/c) = (lambda args #t)
handle-entry :
((or/c 'file 'directory 'link) (and path? relative-path?) (or/c input-port? #f path?) exact-nonnegative-integer? (hash/c symbol? any/c) . -> . (listof (-> any))) = handle-tar-entry
If dest-path is not #f, every path in the archive is prefixed to determine the destination path of the extracted item.
If strip-count is positive, then strip-count path elements are removed from the item path from the archive (before prefixing the path with dest-path); if the item’s path contains strip-count elements, then it is not extracted.
Unless permissive? is true, then archive items with paths containing an up-directory indicator are disallowed, and a link item whose target is an absolute path or contains an up-directory indicator is also disallowed. Absolute paths are always disallowed. A disallowed path triggers an exception.
For each item in the archive, filter-proc is applied to
the item’s path as it appears in the archive;
a destination path that is based on the path in the archive, strip-count, and dest-path–which can be #f if the item’s path does not have strip-count or more elements;
a symbol representing the item’s type—
'file, 'dir, 'link, 'hard-link, 'character-special, 'block-special, 'fifo, 'contiguous-file, 'extended-header, 'extended-header-for-next, or 'unknown— where only 'file, 'dir, or 'link can be unpacked by untar; an exact integer representing the item’s size;
a target path for a 'link type or #f for any other type;
an integer representing the item’s modification date; and
an integer representing the item’s permissions
If the result of filter-proc is #f, then the item is not unpacked.
kind —
one of 'file, 'directory, or 'link. path —
the relative path recorded in the TAR file. content —
an input port that provides the content for a 'file entry, where exactly size bytes must be read from the port before handle-entry returns. For a 'directory entry, content is #f. For a 'link entry, content is a path for the link target. size —
the number of bytes for a 'file entry, and 0 for other entries. attribs —
an immutable hash table mapping symbols to attribute values. The available keys may change, but the currently included keys are the same ones as recognized in tar-entry.
The result of handle-entry is a list of thunks that are called in order after the TAR input is fully unpacked. A result thunk from handle-entry is useful, for example, to set a directory’s modification time after all files have been written to it.
Changed in version 6.3 of package base: Added the #:permissive? argument.
Changed in version 6.7.0.4: Support long paths and long symbolic-link
targets using POSIX.1-2001/pax and GNU
extensions.
Changed in version 8.1.0.5: Added the #:handle-entry argument.
procedure
(handle-tar-entry kind path content size attribs) → (listof (-> any)) kind : (or/c 'file 'directory 'link) path : (and path? relative-path?) content : (or/c input-port? #f path?) size : exact-nonnegative-integer? attribs : (hash/c symbol? any/c)
Added in version 8.1.0.5 of package base.