Variable: jka-compr-compression-info-list
jka-compr-compression-info-list is a customizable variable defined in
jka-cmpr-hook.el.gz.
Value
Large value
(["\\.Z\\'" "compressing" "compress"
("-c")
"uncompressing" "gzip"
("-c" "-q" "-d")
nil t " \235" zlib-decompress-region]
["\\.bz2\\'" "bzip2ing" "bzip2" nil "bunzip2ing" "bzip2"
("-d")
nil t "BZh"]
["\\.tbz2?\\'" "bzip2ing" "bzip2" nil "bunzip2ing" "bzip2"
("-d")
nil nil "BZh"]
["\\.\\(?:tgz\\|svgz\\|sifz\\)\\'" "compressing" "gzip"
("-c" "-q")
"uncompressing" "gzip"
("-c" "-q" "-d")
t nil " \213" zlib-decompress-region]
["\\.g?z\\'" "compressing" "gzip"
("-c" "-q")
"uncompressing" "gzip"
("-c" "-q" "-d")
t t " \213" zlib-decompress-region]
["\\.lz\\'" "Lzip compressing" "lzip"
("-c" "-q")
"Lzip uncompressing" "lzip"
("-c" "-q" "-d")
t t "LZIP"]
["\\.lzma\\'" "LZMA compressing" "lzma"
("-c" "-q" "-z")
"LZMA uncompressing" "lzma"
("-c" "-q" "-d")
t t ""]
["\\.xz\\'" "XZ compressing" "xz"
("-c" "-q")
"XZ uncompressing" "xz"
("-c" "-q" "-d")
t t "\3757zXZ�"]
["\\.txz\\'" "XZ compressing" "xz"
("-c" "-q")
"XZ uncompressing" "xz"
("-c" "-q" "-d")
t nil "\3757zXZ�"]
["\\.dz\\'" nil nil nil "uncompressing" "gzip"
("-c" "-q" "-d")
nil t " \213"]
["\\.zst\\'" "zstd compressing" "zstd"
("-c" "-q")
"zstd uncompressing" "zstd"
("-c" "-q" "-d")
t t "(\265/\375"]
["\\.tzst\\'" "zstd compressing" "zstd"
("-c" "-q")
"zstd uncompressing" "zstd"
("-c" "-q" "-d")
t nil "(\265/\375"])
Documentation
List of vectors that describe available compression techniques.
Each element, which describes a compression technique, is a vector of the form [REGEXP COMPRESS-MSG COMPRESS-PROGRAM COMPRESS-ARGS UNCOMPRESS-MSG UNCOMPRESS-PROGRAM UNCOMPRESS-ARGS APPEND-FLAG STRIP-EXTENSION-FLAG FILE-MAGIC-CHARS UNCOMPRESS-FUNCTION], where:
regexp is a regexp that matches filenames that are
compressed with this format
compress-msg is the message to issue to the user when doing this
type of compression (nil means no message)
compress-program is a program that performs this compression
(nil means visit file in read-only mode)
compress-args is a list of args to pass to the compress program
uncompress-msg is the message to issue to the user when doing this
type of uncompression (nil means no message)
uncompress-program is a program that performs this uncompression
uncompress-args is a list of args to pass to the uncompress program
append-flag is non-nil if this compression technique can be
appended
strip-extension-flag non-nil means strip the regexp from file names
before attempting to set the mode.
file-magic-chars is a string of characters that you would find
at the beginning of a file compressed in this way.
uncompress-function is a function that performs uncompression, if
uncompress-program is not found.
If you set this outside Custom while Auto Compression mode is
already enabled (as it is by default), you have to call
jka-compr-update after setting it to properly update other
variables. Setting this through Custom does that automatically.
This variable was added, or its default value changed, in Emacs 28.1.
Source Code
;; Defined in /usr/src/emacs/lisp/jka-cmpr-hook.el.gz
;; I have this defined so that .Z files are assumed to be in unix
;; compress format; and .gz files, in gzip format, and .bz2 files in bzip fmt.
(defcustom jka-compr-compression-info-list
;;[regexp
;; compr-message compr-prog compr-args
;; uncomp-message uncomp-prog uncomp-args
;; can-append strip-extension-flag file-magic-bytes
;; uncompress-function]
(mapcar 'purecopy
`(["\\.Z\\'"
"compressing" "compress" ("-c")
;; gzip is more common than uncompress. It can only read, not write.
"uncompressing" "gzip" ("-c" "-q" "-d")
nil t "\037\235"
zlib-decompress-region]
;; Formerly, these had an additional arg "-c", but that fails with
;; "Version 0.1pl2, 29-Aug-97." (RedHat 5.1 GNU/Linux) and
;; "Version 0.9.0b, 9-Sept-98".
["\\.bz2\\'"
"bzip2ing" "bzip2" nil
"bunzip2ing" "bzip2" ("-d")
nil t "BZh"]
["\\.tbz2?\\'"
"bzip2ing" "bzip2" nil
"bunzip2ing" "bzip2" ("-d")
nil nil "BZh"]
["\\.\\(?:tgz\\|svgz\\|sifz\\)\\'"
"compressing" "gzip" ("-c" "-q")
"uncompressing" "gzip" ("-c" "-q" "-d")
t nil "\037\213"
zlib-decompress-region]
["\\.g?z\\'"
"compressing" "gzip" ("-c" "-q")
"uncompressing" "gzip" ("-c" "-q" "-d")
t t "\037\213"
zlib-decompress-region]
["\\.lz\\'"
"Lzip compressing" "lzip" ("-c" "-q")
"Lzip uncompressing" "lzip" ("-c" "-q" "-d")
t t "LZIP"]
["\\.lzma\\'"
"LZMA compressing" "lzma" ("-c" "-q" "-z")
"LZMA uncompressing" "lzma" ("-c" "-q" "-d")
t t ""]
["\\.xz\\'"
;; On MacOS, gzip can uncompress xz files.
"XZ compressing" ,(if (featurep 'ns) "gzip" "xz") ("-c" "-q")
"XZ uncompressing" "xz" ("-c" "-q" "-d")
t t "\3757zXZ\0"]
["\\.txz\\'"
"XZ compressing" "xz" ("-c" "-q")
"XZ uncompressing" "xz" ("-c" "-q" "-d")
t nil "\3757zXZ\0"]
;; dzip is gzip with random access. Its compression program can't
;; read/write stdin/out, so .dz files can only be viewed without
;; saving, having their contents decompressed with gzip.
["\\.dz\\'"
nil nil nil
"uncompressing" "gzip" ("-c" "-q" "-d")
nil t "\037\213"]
["\\.zst\\'"
"zstd compressing" "zstd" ("-c" "-q")
"zstd uncompressing" "zstd" ("-c" "-q" "-d")
t t "\050\265\057\375"]
["\\.tzst\\'"
"zstd compressing" "zstd" ("-c" "-q")
"zstd uncompressing" "zstd" ("-c" "-q" "-d")
t nil "\050\265\057\375"]))
"List of vectors that describe available compression techniques.
Each element, which describes a compression technique, is a vector of
the form [REGEXP COMPRESS-MSG COMPRESS-PROGRAM COMPRESS-ARGS
UNCOMPRESS-MSG UNCOMPRESS-PROGRAM UNCOMPRESS-ARGS
APPEND-FLAG STRIP-EXTENSION-FLAG FILE-MAGIC-CHARS UNCOMPRESS-FUNCTION], where:
regexp is a regexp that matches filenames that are
compressed with this format
compress-msg is the message to issue to the user when doing this
type of compression (nil means no message)
compress-program is a program that performs this compression
(nil means visit file in read-only mode)
compress-args is a list of args to pass to the compress program
uncompress-msg is the message to issue to the user when doing this
type of uncompression (nil means no message)
uncompress-program is a program that performs this uncompression
uncompress-args is a list of args to pass to the uncompress program
append-flag is non-nil if this compression technique can be
appended
strip-extension-flag non-nil means strip the regexp from file names
before attempting to set the mode.
file-magic-chars is a string of characters that you would find
at the beginning of a file compressed in this way.
uncompress-function is a function that performs uncompression, if
uncompress-program is not found.
If you set this outside Custom while Auto Compression mode is
already enabled \(as it is by default), you have to call
`jka-compr-update' after setting it to properly update other
variables. Setting this through Custom does that automatically."
:type '(repeat (vector regexp
(choice :tag "Compress Message"
(string :format "%v")
(const :tag "No Message" nil))
(choice :tag "Compress Program"
(string)
(const :tag "None" nil))
(repeat :tag "Compress Arguments" string)
(choice :tag "Uncompress Message"
(string :format "%v")
(const :tag "No Message" nil))
(choice :tag "Uncompress Program"
(string)
(const :tag "None" nil))
(repeat :tag "Uncompress Arguments" string)
(boolean :tag "Append")
(boolean :tag "Strip Extension")
(string :tag "Magic Bytes")
(choice :tag "Uncompress Function"
(symbol)
(const :tag "None" nil))))
:set 'jka-compr-set
:version "28.1" ; add uncompress-function
:group 'jka-compr)