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NAME
zip - Utility for reading and creating 'zip' archives.
DESCRIPTION
The zip module archives and extracts 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 are 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 function.
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_comment() = #zip_comment{comment = undefined | string()}
The record zip_comment just contains the archive comment for a zip archive
zip_file() =
#zip_file{name = undefined | string(),
info = undefined | file:file_info(),
comment = undefined | string(),
offset = undefined | integer() >= 0,
comp_size = undefined | integer() >= 0}
The record zip_file contains the following fields.
name:
the name of the file
info:
file info as in file:read_file_info/1
comment:
the comment for the file in the zip archive
offset:
the offset of the file in the zip archive (used internally)
comp_size:
the compressed size of the file (the uncompressed size is found in info)
EXPORTS
zip(Name, FileList) -> RetValue
zip(Name, FileList, Options) -> RetValue
create(Name, FileList) -> RetValue
create(Name, FileList, Options) -> RetValue
Types:
Name = file:name()
FileList = [FileSpec]
FileSpec = file:name()
| {file:name(), binary()}
| {file:name(), binary(), file:file_info()}
Options = [Option]
Option = memory
| cooked
| verbose
| {comment, Comment}
| {cwd, CWD}
| {compress, What}
| {uncompress, What}
What = all
| [Extension]
| {add, [Extension]}
| {del, [Extension]}
Extension = Comment = CWD = string()
RetValue = {ok, FileName :: file:name()}
| {ok, {FileName :: file:name(), binary()}}
| {error, 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 functions check 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 in raw mode, which is faster but does
not allow a remote (erlang) file server to be used. Adding cooked to the mode list will
override the default and open the zip file without the raw 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 instance unzip/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 will be compressed. It is by default set to all. The following
values of What 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 will be uncompressed. It is by default set to [".Z", ".zip",
".zoo", ".arc", ".lzh", ".arj"]. The following values of What 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
Types:
Archive = file:name() | binary()
Options = [Option]
Option = {file_list, FileList}
| keep_old_files
| verbose
| memory
| {file_filter, FileFilter}
| {cwd, CWD}
FileList = [file:name()]
FileBinList = [{file:name(), binary()}]
FileFilter = fun((ZipFile) -> boolean())
CWD = string()
ZipFile = zip_file()
RetValue = {ok, FileList}
| {ok, FileBinList}
| {error, Reason :: term()}
| {error, {Name :: file:name(), 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, the unzip/2 function will only extract the files whose names are included in FileList.
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 in raw mode, which is faster but does
not allow a remote (erlang) file server to be used. Adding cooked to the mode list will
override the default and open the zip file without the raw 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, the unzip/2 function will not overwrite any
existing files. Note that even with the memory 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}, where Binary is a binary containing the extracted data of
the file named Filename 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}
Types:
Fun = fun((FileInArchive, GetInfo, GetBin, AccIn) -> AccOut)
FileInArchive = file:name()
GetInfo = fun(() -> file:file_info())
GetBin = fun(() -> binary())
Acc0 = Acc1 = AccIn = AccOut = term()
Archive = file:name() | {file:name(), binary()}
Reason = term()
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) -> RetValue
table(Archive) -> RetValue
table(Archive, Options) -> RetValue
Types:
Archive = file:name() | binary()
RetValue = {ok, CommentAndFiles} | {error, Reason :: term()}
CommentAndFiles = [zip_comment() | zip_file()]
Options = [Option]
Option = cooked
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 in raw mode, which is faster but does
not allow a remote (erlang) file server to be used. Adding cooked to the mode list will
override the default and open the zip file without the raw option.
t(Archive) -> ok
Types:
Archive = file:name() | 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) -> ok
Types:
Archive = file:name() | binary() | ZipHandle
ZipHandle = pid()
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}
Types:
Archive = file:name() | binary()
ZipHandle = pid()
Options = [Option]
Option = cooked | memory | {cwd, CWD :: string()}
Reason = term()
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) -> {ok, Result} | {error, Reason}
Types:
Result = [zip_comment() | zip_file()]
ZipHandle = pid()
Reason = term()
The zip_list_dir/1 function returns the file list of an open zip archive. The first returned
element is the zip archive comment.
zip_get(ZipHandle) -> {ok, [Result]} | {error, Reason}
zip_get(FileName, ZipHandle) -> {ok, Result} | {error, Reason}
Types:
FileName = file:name()
ZipHandle = pid()
Result = file:name() | {file:name(), binary()}
Reason = term()
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}
Types:
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.