zip
Utility for reading and creating 'zip' archives.
The zip
module archives and extract files to and from a zip
archive. The zip format is specified by the "ZIP Appnote.txt" file
available on PKWare's website www.pkware.com.
The zip module supports zip archive versions up to 6.1. However, password-protection and Zip64 is not supported.
By convention, the name of a zip file should end in ".zip
".
To abide to the convention, you'll need to add ".zip
" yourself
to the name.
Zip archives are created with the
zip/2 or the
zip/3 function. (They are
also available as create
, to resemble the erl_tar
module.)
To extract files from a zip archive, use the
unzip/1 or the
unzip/2 function. (They are
also available as extract
.)
To fold a function over all files in a zip archive, use the foldl_3.
To return a list of the files in a zip archive, use the
list_dir/1 or the
list_dir/2 function. (They
are also available as table
.)
To print a list of files to the Erlang shell, use either the t/1 or tt/1 function.
In some cases, it is desirable to open a zip archive, and to unzip files from it file by file, without having to reopen the archive. The functions zip_open, zip_get, zip_list_dir and zip_close do this.
LIMITATIONS
Zip64 archives are not currently supported.
Password-protected and encrypted archives are not currently supported
Only the DEFLATE (zlib-compression) and the STORE (uncompressed data) zip methods are supported.
The size of the archive is limited to 2 G-byte (32 bits).
Comments for individual files is not supported when creating zip archives. The zip archive comment for the whole zip archive is supported.
There is currently no support for altering an existing zip archive. To add or remove a file from an archive, the whole archive must be recreated.
DATA TYPES
zip_file()
The record zip_file
contains the following fields.
name = string()
-
the name of the file
info = file_info()
-
file info as in file:read_file_info/1
comment = string()
-
the comment for the file in the zip archive
offset = integer()
-
the offset of the file in the zip archive (used internally)
comp_size = integer()
-
the compressed size of the file (the uncompressed size is found in
info
)
zip_comment
The record zip_comment
just contains the archive comment for
a zip archive
comment = string()
-
the comment for the zip archive
Functions
zip(Name, FileList) -> RetValue
zip(Name, FileList, Options) -> RetValue
create(Name, FileList) -> RetValue
create(Name, FileList, Options) -> RetValue
Name = filename()
FileList = [FileSpec]
FileSpec = filename() | {filename(), binary()} | {filename(), binary(), #file_info{}}
Options = [Option]
Option = memory | cooked | verbose | {comment, Comment} | {cwd, CWD} | {compress, What} | {uncompress, What}
What = all | [Extension] | {add, [Extension]} | {del, [Extension]}
Extension = string()
Comment = CWD = string()
RetValue = {ok, Name} | {ok, {Name, binary()}} | {error, Reason}
Reason = term()
The zip
function creates a
zip archive containing the files specified in FileList
.
As synonyms, the functions create/2
and create/3
are provided, to make it resemble the erl_tar
module.
The file-list is a list of files, with paths relative to the current directory, they will be stored with this path in the archive. Files may also be specified with data in binaries, to create an archive directly from data.
Files will be compressed using the DEFLATE compression, as
described in the Appnote.txt file. However, files will be
stored without compression if they already are compressed.
The zip/2
and zip/3
checks the file extension
to see whether the file should be stored without compression.
Files with the following extensions are not compressed:
.Z
, .zip
, .zoo
, .arc
, .lzh
,
.arj
.
It is possible to override the default behavior and
explicitly control what types of files that should be
compressed by using the {compress, What}
and
{uncompress, What}
options. It is possible to have
several compress
and uncompress
options. In
order to trigger compression of a file, its extension must
match with the
compress
condition and must not match the
uncompress
condition. For example if compress
is
set to ["gif", "jpg"]
and uncompress
is set to
["jpg"]
, only files with "gif"
as extension will
be compressed. No other files will be compressed.
The following options are available:
cooked
-
By default, the
open/2
function will open the zip file inraw
mode, which is faster but does not allow a remote (erlang) file server to be used. Addingcooked
to the mode list will override the default and open the zip file without theraw
option. The same goes for the files added. verbose
-
Print an informational message about each file being added.
memory
-
The output will not be to a file, but instead as a tuple
{FileName, binary()}
. The binary will be a full zip archive with header, and can be extracted with for instanceunzip/2
. {comment, Comment}
-
Add a comment to the zip-archive.
{cwd, CWD}
-
Use the given directory as current directory, it will be prepended to file names when adding them, although it will not be in the zip-archive. (Acting like a file:set_cwd/1, but without changing the global cwd property.)
{compress, What}
-
Controls what types of files that will be compressed. It is by default set to
all
. The following values ofWhat
are allowed:all
means that all files will be compressed (as long as they pass the
uncompress
condition).[Extension]
means that only files with exactly these extensions will be compressed.
{add,[Extension]}
adds these extensions to the list of compress extensions.
{del,[Extension]}
deletes these extensions from the list of compress extensions.
{uncompress, What}
-
Controls what types of files that will be uncompressed. It is by default set to
[".Z",".zip",".zoo",".arc",".lzh",".arj"]
. The following values ofWhat
are allowed:all
means that no files will be compressed.
[Extension]
means that files with these extensions will be uncompressed.
{add,[Extension]}
adds these extensions to the list of uncompress extensions.
{del,[Extension]}
deletes these extensions from the list of uncompress extensions.
unzip(Archive) -> RetValue
unzip(Archive, Options) -> RetValue
extract(Archive) -> RetValue
extract(Archive, Options) -> RetValue
Archive = filename() | binary()
Options = [Option]
Option = {file_list, FileList} | keep_old_files | verbose | memory | {file_filter, FileFilter} | {cwd, CWD}
FileList = [filename()]
FileBinList = [{filename(),binary()}]
FileFilter = fun(ZipFile) -> true | false
CWD = string()
ZipFile = zip_file()
RetValue = {ok,FileList} | {ok,FileBinList} | {error, Reason} | {error, {Name, Reason}}
Reason = term()
The
unzip/1
function extracts
all files from a zip archive. The
unzip/2
function provides options
to extract some files, and more.
If the Archive
argument is given as a binary,
the contents of the binary is assumed to be a zip archive,
otherwise it should be a filename.
The following options are available:
{file_list, FileList}
-
By default, all files will be extracted from the zip archive. With the
{file_list,FileList}
option, theunzip/2
function will only extract the files whose names are included inFileList
. The full paths, including the names of all sub directories within the zip archive, must be specified. cooked
-
By default, the
open/2
function will open the zip file inraw
mode, which is faster but does not allow a remote (erlang) file server to be used. Addingcooked
to the mode list will override the default and open zip file without theraw
option. The same goes for the files extracted. keep_old_files
-
By default, all existing files with the same name as file in the zip archive will be overwritten. With the
keep_old_files
option, theunzip/2
function will not overwrite any existing files. Not that even with thememory
option given, which means that no files will be overwritten, files existing will be excluded from the result. verbose
-
Print an informational message as each file is being extracted.
memory
-
Instead of extracting to the current directory, the
memory
option will give the result as a list of tuples{Filename, Binary}
, whereBinary
is a binary containing the extracted data of the file namedFilename
in the zip archive. {cwd, CWD}
-
Use the given directory as current directory, it will be prepended to file names when extracting them from the zip-archive. (Acting like a file:set_cwd/1, but without changing the global cwd property.)
foldl(Fun, Acc0, Archive) -> {ok, Acc1} | {error, Reason}
Fun = fun(FileInArchive, GetInfo, GetBin, AccIn) -> AccOut
FileInArchive = filename()
GetInfo = fun() -> #file_info{}
GetBin = fun() -> binary()
Acc0 = Acc1 = AccIn = AccOut = term()
Archive = filename() | {filename(), binary()}
The foldl/3
function
calls Fun(FileInArchive, GetInfo, GetBin, AccIn)
on
successive files in the Archive
, starting with AccIn
== Acc0
. FileInArchive
is the name that the file
has in the archive. GetInfo
is a fun that returns info
about the the file. GetBin
returns the contents of the
file. Both GetInfo
and GetBin
must be called
within the Fun
. Their behavior is undefined if they are
called outside the context of the Fun
. The Fun
must return a new accumulator which is passed to the next
call. foldl/3
returns the final value of the
accumulator. Acc0
is returned if the archive is
empty. It is not necessary to iterate over all files in the
archive. The iteration may be ended prematurely in a
controlled manner by throwing an exception.
For example:
>Name = "dummy.zip".
"dummy.zip" >{ok, {Name, Bin}} = zip:create(Name, [{"foo", <<"FOO">>}, {"bar", <<"BAR">>}], [memory]).
{ok,{"dummy.zip", <<80,75,3,4,20,0,0,0,0,0,74,152,97,60,171,39,212,26,3,0, 0,0,3,0,0,...>>}} >{ok, FileSpec} = zip:foldl(fun(N, I, B, Acc) -> [{N, B(), I()} | Acc] end, [], {Name, Bin}).
{ok,[{"bar",<<"BAR">>, {file_info,3,regular,read_write, {{2010,3,1},{19,2,10}}, {{2010,3,1},{19,2,10}}, {{2010,3,1},{19,2,10}}, 54,1,0,0,0,0,0}}, {"foo",<<"FOO">>, {file_info,3,regular,read_write, {{2010,3,1},{19,2,10}}, {{2010,3,1},{19,2,10}}, {{2010,3,1},{19,2,10}}, 54,1,0,0,0,0,0}}]} >{ok, {Name, Bin}} = zip:create(Name, lists:reverse(FileSpec), [memory]).
{ok,{"dummy.zip", <<80,75,3,4,20,0,0,0,0,0,74,152,97,60,171,39,212,26,3,0, 0,0,3,0,0,...>>}} >catch zip:foldl(fun("foo", _, B, _) -> throw(B()); (_, _, _, Acc) -> Acc end, [], {Name, Bin}).
<<"FOO">>
list_dir(Archive) -> RetValue
list_dir(Archive, Options)
table(Archive) -> RetValue
table(Archive, Options)
Archive = filename() | binary()
RetValue = {ok, [Comment, Files]} | {error, Reason}
Comment = zip_comment()
Files = [zip_file()]
Options = [Option]
Option = cooked
Reason = term()
The
list_dir/1
function retrieves
the names of all files in the zip archive Archive
. The
list_dir/2
function provides options.
As synonyms, the functions table/2
and table/3
are provided, to make it resemble the erl_tar
module.
The result value is the tuple {ok, List}
, where List
contains the zip archive comment as the first element.
The following options are available:
cooked
-
By default, the
open/2
function will open the zip file inraw
mode, which is faster but does not allow a remote (erlang) file server to be used. Addingcooked
to the mode list will override the default and open zip file without theraw
option.
t(Archive)
Archive = filename() | binary() | ZipHandle
ZipHandle = pid()
The
t/1
function prints the names
of all files in the zip archive Archive
to the Erlang shell.
(Similar to "tar t
".)
tt(Archive)
Archive = filename() | binary()
The
tt/1
function prints names and
information about all files in the zip archive Archive
to
the Erlang shell. (Similar to "tar tv
".)
zip_open(Archive) -> {ok, ZipHandle} | {error, Reason}
zip_open(Archive, Options) -> {ok, ZipHandle} | {error, Reason}
Archive = filename() | binary()
Options = [Option]
Options = cooked | memory | {cwd, CWD}
CWD = string()
ZipHandle = pid()
The
zip_open
function opens a
zip archive, and reads and saves its directory. This
means that subsequently reading files from the archive will be
faster than unzipping files one at a time with unzip
.
The archive must be closed with zip_close/1
.
zip_list_dir(ZipHandle) -> Result | {error, Reason}
Result = [ZipComment, ZipFile...]
ZipComment = #zip_comment{}
ZipFile = #zip_file{}
ZipHandle = pid()
The
zip_list_dir/1
function
returns the file list of an open zip archive.
zip_get(ZipHandle) -> {ok, [Result]} | {error, Reason}
zip_get(FileName, ZipHandle) -> {ok, Result} | {error, Reason}
FileName = filename()
ZipHandle = pid()
Result = filename() | {filename(), binary()}
The
zip_get
function extracts
one or all files from an open archive.
The files will be unzipped to memory or to file, depending on
the options given to the zip_open
function when the
archive was opened.
zip_close(ZipHandle) -> ok | {error, einval}
ZipHandle = pid()
The
zip_close/1
function closes
a zip archive, previously opened with zip_open
. All
resources are closed, and the handle should not be used after
closing.