Windows PowerShell command on Get-command unzip

Manual Pages for UNIX Operating System command usage for man unzip

Misc. Reference Manual Pages UNZIP(1L)

NAME

unzip - list, test and extract compressed files in a ZIP

SYNOPSIS

unzip [-Z] [-cflptTuvz[abjnoqsCDKLMVWX$/:^]] file[.zip]

[file(s) ...] [-x xfile(s) ...] [-d exdir]

DESCRIPTION

unzip will list, test, or extract files from a ZIP archive,

commonly found on MS-DOS systems. The default behavior

(with no options) is to extract into the current directory (and subdirectories below it) all files from the specified ZIP archive. A companion program, zip(1L), creates ZIP archives; both programs are compatible with archives created

by PKWARE's PKZIP and PKUNZIP for MS-DOS, but in many cases

the program options or default behaviors differ. ARGUMENTS file[.zip] Path of the ZIP archive(s). If the file specification is a wildcard, each matching file is processed in an

order determined by the operating system (or file sys-

tem). Only the filename can be a wildcard; the path itself cannot. Wildcard expressions are similar to those supported in commonly used Unix shells (sh, ksh, csh) and may contain: * matches a sequence of 0 or more characters ? matches exactly 1 character [...] matches any single character found inside the brackets; ranges are specified by a beginning character, a hyphen, and an ending character. If

an exclamation point or a caret (`!' or `^') fol-

lows the left bracket, then the range of charac-

ters within the brackets is complemented (that is, anything except the characters inside the brackets is considered a match). To specify a verbatim

left bracket, the three-character sequence ``[[]''

has to be used. (Be sure to quote any character that might otherwise be

interpreted or modified by the operating system, par-

ticularly under Unix and VMS.) If no matches are found, the specification is assumed to be a literal filename; and if that also fails, the suffix .zip is

appended. Note that self-extracting ZIP files are sup-

ported, as with any other ZIP archive; just specify the .exe suffix (if any) explicitly.

Info-ZIP Last change: 28 December 2007 (v5.53) 1

Misc. Reference Manual Pages UNZIP(1L) [file(s)] An optional list of archive members to be processed, separated by spaces. (VMS versions compiled with VMSCLI defined must delimit files with commas instead.

See -v in OPTIONS below.) Regular expressions (wild-

cards) may be used to match multiple members; see above. Again, be sure to quote expressions that would

otherwise be expanded or modified by the operating sys-

tem.

[-x xfile(s)]

An optional list of archive members to be excluded from processing. Since wildcard characters normally match (`/') directory separators (for exceptions see the

option -W), this option may be used to exclude any

files that are in subdirectories. For example, ``unzip

foo *.[ch] -x */*'' would extract all C source files in

the main directory, but none in any subdirectories.

Without the -x option, all C source files in all direc-

tories within the zipfile would be extracted.

[-d exdir]

An optional directory to which to extract files. By default, all files and subdirectories are recreated in

the current directory; the -d option allows extraction

in an arbitrary directory (always assuming one has per-

mission to write to the directory). This option need not appear at the end of the command line; it is also accepted before the zipfile specification (with the

normal options), immediately after the zipfile specifi-

cation, or between the file(s) and the -x option. The

option and directory may be concatenated without any white space between them, but note that this may cause normal shell behavior to be suppressed. In particular,

``-d ~'' (tilde) is expanded by Unix C shells into the

name of the user's home directory, but ``-d~'' is

treated as a literal subdirectory ``~'' of the current directory. OPTIONS

Note that, in order to support obsolescent hardware, unzip's

usage screen is limited to 22 or 23 lines and should there-

fore be considered only a reminder of the basic unzip syntax

rather than an exhaustive list of all possible flags. The exhaustive list follows:

-Z zipinfo(1L) mode. If the first option on the command

line is -Z, the remaining options are taken to be

zipinfo(1L) options. See the appropriate manual page for a description of these options.

-A [OS/2, Unix DLL] print extended help for the DLL's

Info-ZIP Last change: 28 December 2007 (v5.53) 2

Misc. Reference Manual Pages UNZIP(1L) programming interface (API).

-c extract files to stdout/screen (``CRT''). This option

is similar to the -p option except that the name of

each file is printed as it is extracted, the -a option

is allowed, and ASCII-EBCDIC conversion is automati-

cally performed if appropriate. This option is not

listed in the unzip usage screen.

-f freshen existing files, i.e., extract only those files

that already exist on disk and that are newer than the

disk copies. By default unzip queries before overwrit-

ing, but the -o option may be used to suppress the

queries. Note that under many operating systems, the TZ (timezone) environment variable must be set

correctly in order for -f and -u to work properly

(under Unix the variable is usually set automatically). The reasons for this are somewhat subtle but have to do

with the differences between DOS-format file times

(always local time) and Unix-format times (always in

GMT/UTC) and the necessity to compare the two. A typi-

cal TZ value is ``PST8PDT'' (US Pacific time with automatic adjustment for Daylight Savings Time or ``summer time'').

-l list archive files (short format). The names,

uncompressed file sizes and modification dates and times of the specified files are printed, along with totals for all files specified. If UnZip was compiled

with OS2_EAS defined, the -l option also lists columns

for the sizes of stored OS/2 extended attributes (EAs) and OS/2 access control lists (ACLs). In addition, the zipfile comment and individual file comments (if any)

are displayed. If a file was archived from a single-

case file system (for example, the old MS-DOS FAT file

system) and the -L option was given, the filename is

converted to lowercase and is prefixed with a caret (^).

-p extract files to pipe (stdout). Nothing but the file

data is sent to stdout, and the files are always extracted in binary format, just as they are stored (no conversions).

-t test archive files. This option extracts each speci-

fied file in memory and compares the CRC (cyclic redun-

dancy check, an enhanced checksum) of the expanded file with the original file's stored CRC value.

-T [most OSes] set the timestamp on the archive(s) to that

of the newest file in each one. This corresponds to

zip's -go option except that it can be used on wildcard

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Misc. Reference Manual Pages UNZIP(1L)

zipfiles (e.g., ``unzip -T \*.zip'') and is much fas-

ter.

-u update existing files and create new ones if needed.

This option performs the same function as the -f

option, extracting (with query) files that are newer than those with the same name on disk, and in addition it extracts those files that do not already exist on

disk. See -f above for information on setting the

timezone properly.

-v list archive files (verbose format) or show diagnostic

version info. This option has evolved and now behaves as both an option and a modifier. As an option it has two purposes: when a zipfile is specified with no

other options, -v lists archive files verbosely, adding

to the basic -l info the compression method, compressed

size, compression ratio and 32-bit CRC. In contrast to

most of the competing utilities, unzip removes the 12

additional header bytes of encrypted entries from the compressed size numbers. Therefore, compressed size and compression ratio figures are independent of the

entry's encryption status and show the correct compres-

sion performance. (The complete size of the encrypted compressed data stream for zipfile entries is reported by the more verbose zipinfo(1L) reports, see the separate manual.) When no zipfile is specified (that

is, the complete command is simply ``unzip -v''), a

diagnostic screen is printed. In addition to the nor-

mal header with release date and version, unzip lists

the home Info-ZIP ftp site and where to find a list of

other ftp and non-ftp sites; the target operating sys-

tem for which it was compiled, as well as (possibly) the hardware on which it was compiled, the compiler and version used, and the compilation date; any special compilation options that might affect the program's operation (see also DECRYPTION below); and any options stored in environment variables that might do the same (see ENVIRONMENT OPTIONS below). As a modifier it

works in conjunction with other options (e.g., -t) to

produce more verbose or debugging output; this is not yet fully implemented but will be in future releases.

-z display only the archive comment.

MODIFIERS

-a convert text files. Ordinarily all files are extracted

exactly as they are stored (as ``binary'' files). The

-a option causes files identified by zip as text files

(those with the `t' label in zipinfo listings, rather

than `b') to be automatically extracted as such, con-

verting line endings, end-of-file characters and the

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Misc. Reference Manual Pages UNZIP(1L) character set itself as necessary. (For example, Unix

files use line feeds (LFs) for end-of-line (EOL) and

have no end-of-file (EOF) marker; Macintoshes use car-

riage returns (CRs) for EOLs; and most PC operating

systems use CR+LF for EOLs and control-Z for EOF. In

addition, IBM mainframes and the Michigan Terminal Sys-

tem use EBCDIC rather than the more common ASCII char-

acter set, and NT supports Unicode.) Note that zip's identification of text files is by no means perfect; some ``text'' files may actually be binary and vice

versa. unzip therefore prints ``[text]'' or

``[binary]'' as a visual check for each file it

extracts when using the -a option. The -aa option

forces all files to be extracted as text, regardless of

the supposed file type. On VMS, see also -S.

-b [general] treat all files as binary (no text conver-

sions). This is a shortcut for ---a.

-b [Tandem] force the creation files with filecode type

180 ('C') when extracting Zip entries marked as "text".

(On Tandem, -a is enabled by default, see above).

-b [VMS] auto-convert binary files (see -a above) to

fixed-length, 512-byte record format. Doubling the

option (-bb) forces all files to be extracted in this

format. When extracting to standard output (-c or -p

option in effect), the default conversion of text

record delimiters is disabled for binary (-b) resp. all

(-bb) files.

-B [Unix only, and only if compiled with UNIXBACKUP

defined] save a backup copy of each overwritten file with a tilde appended (e.g., the old copy of ``foo'' is renamed to ``foo~''). This is similar to the default behavior of emacs(1) in many locations.

-C use case-insensitive matching for the selection of

archive entries from the command-line list of extract

selection patterns. unzip's philosophy is ``you get

what you ask for'' (this is also responsible for the

-L/-U change; see the relevant options below). Because

some file systems are fully case-sensitive (notably

those under the Unix operating system) and because both

ZIP archives and unzip itself are portable across plat-

forms, unzip's default behavior is to match both wild-

card and literal filenames case-sensitively. That is,

specifying ``makefile'' on the command line will only match ``makefile'' in the archive, not ``Makefile'' or

``MAKEFILE'' (and similarly for wildcard specifica-

tions). Since this does not correspond to the behavior of many other operating/file systems (for example, OS/2

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Misc. Reference Manual Pages UNZIP(1L) HPFS, which preserves mixed case but is not sensitive

to it), the -C option may be used to force all filename

matches to be case-insensitive. In the example above,

all three files would then match ``makefile'' (or

``make*'', or similar). The -C option affects file

specs in both the normal file list and the excluded-

file list (xlist).

Please note that the -C option does neither affect the

search for the zipfile(s) nor the matching of archive entries to existing files on the extraction path. On a

case-sensitive file system, unzip will never try to

overwrite a file ``FOO'' when extracting an entry ``foo''!

-D skip restoration of timestamps for extracted items.

Normally, unzip tries to restore all meta-information

for extracted items that are supplied in the Zip archive (and do not require priviledges or impose a

security risk). By specifying -D, unzip is told to

suppress restoration of timestamps for directories explicitly created from Zip archive entries. This option only applies to ports that support setting timestamps for directories (currently ATheOS, BeOS,

MacOS, OS/2, Unix, VMS, Win32, for other unzip ports,

-D has no effect). The duplicated option -DD forces

suppression of timestamp restoration for all extracted entries (files and directories). This option results in setting the timestamps for all extracted entries to the current time.

On VMS, the default setting for this option is -D for

consistency with the behaviour of BACKUP: file times-

tamps are restored, timestamps of extracted directories are left at the current time. To enable restoration of

directory timestamps, the negated option --D should be

specified. On VMS, the option -D disables timestamp

restoration for all extracted Zip archive items.

-E [MacOS only] display contents of MacOS extra field dur-

ing restore operation.

-F [Acorn only] suppress removal of NFS filetype extension

from stored filenames.

-F [non-Acorn systems supporting long filenames with

embedded commas, and only if compiled with

ACORN_FTYPE_NFS defined] translate filetype information

from ACORN RISC OS extra field blocks into a NFS file-

type extension and append it to the names of the extracted files. (When the stored filename appears to already have an appended NFS filetype extension, it is

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Misc. Reference Manual Pages UNZIP(1L) replaced by the info from the extra field.)

-i [MacOS only] ignore filenames stored in MacOS extra

fields. Instead, the most compatible filename stored in the generic part of the entry's header is used.

-j junk paths. The archive's directory structure is not

recreated; all files are deposited in the extraction directory (by default, the current one).

-J [BeOS only] junk file attributes. The file's BeOS file

attributes are not restored, just the file's data.

-J [MacOS only] ignore MacOS extra fields. All Macintosh

specific info is skipped. Data-fork and resource-fork

are restored as separate files.

-K [AtheOS, BeOS, Unix only] retain SUID/SGID/Tacky file

attributes. Without this flag, these attribute bits are cleared for security reasons.

-L convert to lowercase any filename originating on an

uppercase-only operating system or file system. (This

was unzip's default behavior in releases prior to 5.11;

the new default behavior is identical to the old

behavior with the -U option, which is now obsolete and

will be removed in a future release.) Depending on the

archiver, files archived under single-case file systems

(VMS, old MS-DOS FAT, etc.) may be stored as all-

uppercase names; this can be ugly or inconvenient when

extracting to a case-preserving file system such as

OS/2 HPFS or a case-sensitive one such as under Unix.

By default unzip lists and extracts such filenames

exactly as they're stored (excepting truncation, conversion of unsupported characters, etc.); this

option causes the names of all files from certain sys-

tems to be converted to lowercase. The -LL option

forces conversion of every filename to lowercase, regardless of the originating file system.

-M pipe all output through an internal pager similar to

the Unix more(1) command. At the end of a screenful of

output, unzip pauses with a ``--More--'' prompt; the

next screenful may be viewed by pressing the Enter

(Return) key or the space bar. unzip can be terminated

by pressing the ``q'' key and, on some systems, the

Enter/Return key. Unlike Unix more(1), there is no

forward-searching or editing capability. Also, unzip

doesn't notice if long lines wrap at the edge of the screen, effectively resulting in the printing of two or more lines and the likelihood that some text will scroll off the top of the screen before being viewed.

Info-ZIP Last change: 28 December 2007 (v5.53) 7

Misc. Reference Manual Pages UNZIP(1L) On some systems the number of available lines on the

screen is not detected, in which case unzip assumes the

height is 24 lines.

-n never overwrite existing files. If a file already

exists, skip the extraction of that file without

prompting. By default unzip queries before extracting

any file that already exists; the user may choose to overwrite only the current file, overwrite all files, skip extraction of the current file, skip extraction of all existing files, or rename the current file.

-N [Amiga] extract file comments as Amiga filenotes. File

comments are created with the -c option of zip(1L), or

with the -N option of the Amiga port of zip(1L), which

stores filenotes as comments.

-o overwrite existing files without prompting. This is a

dangerous option, so use it with care. (It is often

used with -f, however, and is the only way to overwrite

directory EAs under OS/2.)

-P password

use password to decrypt encrypted zipfile entries (if

any). THIS IS INSECURE! Many multi-user operating

systems provide ways for any user to see the current

command line of any other user; even on stand-alone

systems there is always the threat of over-the-shoulder

peeking. Storing the plaintext password as part of a command line in an automated script is even worse.

Whenever possible, use the non-echoing, interactive

prompt to enter passwords. (And where security is truly important, use strong encryption such as Pretty Good Privacy instead of the relatively weak encryption provided by standard zipfile utilities.)

-q perform operations quietly (-qq = even quieter). Ordi-

narily unzip prints the names of the files it's

extracting or testing, the extraction methods, any file or zipfile comments that may be stored in the archive, and possibly a summary when finished with each archive.

The -q[q] options suppress the printing of some or all

of these messages.

-s [OS/2, NT, MS-DOS] convert spaces in filenames to

underscores. Since all PC operating systems allow

spaces in filenames, unzip by default extracts

filenames with spaces intact (e.g., ``EA DATA. SF'').

This can be awkward, however, since MS-DOS in particu-

lar does not gracefully support spaces in filenames. Conversion of spaces to underscores can eliminate the awkwardness in some cases.

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Misc. Reference Manual Pages UNZIP(1L)

-S [VMS] convert text files (-a, -aa) into Stream_LF

record format, instead of the text-file default,

variable-length record format. (Stream_LF is the

default record format of VMS unzip. It is applied

unless conversion (-a, -aa and/or -b, -bb) is requested

or a VMS-specific entry is processed.)

-U (obsolete; to be removed in a future release) leave

filenames uppercase if created under MS-DOS, VMS, etc.

See -L above.

-V retain (VMS) file version numbers. VMS files can be

stored with a version number, in the format

file.ext;##. By default the ``;##'' version numbers

are stripped, but this option allows them to be retained. (On file systems that limit filenames to particularly short lengths, the version numbers may be truncated or stripped regardless of this option.)

-W [only when WILD_STOP_AT_DIR compile-time option

enabled] modifies the pattern matching routine so that

both `?' (single-char wildcard) and `*' (multi-char

wildcard) do not match the directory separator charac-

ter `/'. (The two-character sequence ``**'' acts as a

multi-char wildcard that includes the directory separa-

tor in its matched characters.) Examples: "*.c" matches "foo.c" but not "mydir/foo.c" "**.c" matches both "foo.c" and "mydir/foo.c" "*/*.c" matches "bar/foo.c" but not "baz/bar/foo.c" "??*/*" matches "ab/foo" and "abc/foo" but not "a/foo" or "a/b/foo" This modified behaviour is equivalent to the pattern matching style used by the shells of some of UnZip's supported target OSs (one example is Acorn RISC OS). This option may not be available on systems where the Zip archive's internal directory separator character `/' is allowed as regular character in native operating

system filenames. (Currently, UnZip uses the same pat-

tern matching rules for both wildcard zipfile specifi-

cations and zip entry selection patterns in most ports. For systems allowing `/' as regular filename character,

the -W option would not work as expected on a wildcard

zipfile specification.)

-X [VMS, Unix, OS/2, NT] restore owner/protection info

(UICs) under VMS, or user and group info (UID/GID)

under Unix, or access control lists (ACLs) under cer-

tain network-enabled versions of OS/2 (Warp Server with

IBM LAN Server/Requester 3.0 to 5.0; Warp Connect with IBM Peer 1.0), or security ACLs under Windows NT. In

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Misc. Reference Manual Pages UNZIP(1L) most cases this will require special system privileges,

and doubling the option (-XX) under NT instructs unzip

to use privileges for extraction; but under Unix, for example, a user who belongs to several groups can restore files owned by any of those groups, as long as the user IDs match his or her own. Note that ordinary

file attributes are always restored--this option

applies only to optional, extra ownership info avail-

able on some operating systems. [NT's access control lists do not appear to be especially compatible with

OS/2's, so no attempt is made at cross-platform porta-

bility of access privileges. It is not clear under what conditions this would ever be useful anyway.]

-$ [MS-DOS, OS/2, NT] restore the volume label if the

extraction medium is removable (e.g., a diskette).

Doubling the option (-$$) allows fixed media (hard

disks) to be labelled as well. By default, volume labels are ignored.

-/ extensions

[Acorn only] overrides the extension list supplied by

Unzip$Ext environment variable. During extraction,

filename extensions that match one of the items in this extension list are swapped in front of the base name of the extracted file.

-: [all but Acorn, VM/CMS, MVS, Tandem] allows to extract

archive members into locations outside of the current `` extraction root folder''. For security reasons,

unzip normally removes ``parent dir'' path components

(``../'') from the names of extracted file. This

safety feature (new for version 5.50) prevents unzip

from accidentally writing files to ``sensitive'' areas

outside the active extraction folder tree head. The -:

option lets unzip switch back to its previous, more

liberal behaviour, to allow exact extraction of (older)

archives that used ``../'' components to create multi-

ple directory trees at the level of the current extrac-

tion folder. This option does not enable writing explicitly to the root directory (``/''). To achieve this, it is necessary to set the extraction target

folder to root (e.g. -d / ). However, when the -:

option is specified, it is still possible to implicitly write to the root directory by specifying enough ``../'' path components within the zip archive. Use this option with extreme caution.

-^ [Unix only] allow control characters in names of

extracted ZIP archive entries. On Unix, a file name

may contain any (8-bit) character code with the two

exception '/' (directory delimiter) and NUL (0x00, the

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Misc. Reference Manual Pages UNZIP(1L) C string termination indicator), unless the specific

file system has more restrictive conventions. Gen-

erally, this allows to embed ASCII control characters (or even sophisticated control sequences) in file

names, at least on 'native' Unix file systems. How-

ever, it may be highly suspicious to make use of this Unix "feature". Embedded control characters in file names might have nasty side effects when displayed on

screen by some listing code without sufficient filter-

ing. And, for ordinary users, it may be difficult to handle such file names (e.g. when trying to specify it

for open, copy, move, or delete operations). There-

fore, unzip applies a filter by default that removes

potentially dangerous control characters from the

extracted file names. The -^ option allows to override

this filter in the rare case that embedded filename control characters are to be intentionally restored. ENVIRONMENT OPTIONS

unzip's default behavior may be modified via options placed

in an environment variable. This can be done with any

option, but it is probably most useful with the -a, -L, -C,

-q, -o, or -n modifiers: make unzip auto-convert text files

by default, make it convert filenames from uppercase systems

to lowercase, make it match names case-insensitively, make

it quieter, or make it always overwrite or never overwrite

files as it extracts them. For example, to make unzip act

as quietly as possible, only reporting errors, one would use one of the following commands: Unix Bourne shell:

UNZIP=-qq; export UNZIP

Unix C shell:

setenv UNZIP -qq

OS/2 or MS-DOS:

set UNZIP=-qq

VMS (quotes for lowercase):

define UNZIP_OPTS "-qq"

Environment options are, in effect, considered to be just

like any other command-line options, except that they are

effectively the first options on the command line. To over-

ride an environment option, one may use the ``minus opera-

tor'' to remove it. For instance, to override one of the

quiet-flags in the example above, use the command

unzip --q[other options] zipfile

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Misc. Reference Manual Pages UNZIP(1L) The first hyphen is the normal switch character, and the second is a minus sign, acting on the q option. Thus the

effect here is to cancel one quantum of quietness. To can-

cel both quiet flags, two (or more) minuses may be used:

unzip -t--q zipfile

unzip ---qt zipfile

(the two are equivalent). This may seem awkward or confus-

ing, but it is reasonably intuitive: just ignore the first hyphen and go from there. It is also consistent with the behavior of Unix nice(1). As suggested by the examples above, the default variable

names are UNZIP_OPTS for VMS (where the symbol used to

install unzip as a foreign command would otherwise be con-

fused with the environment variable), and UNZIP for all other operating systems. For compatibility with zip(1L), UNZIPOPT is also accepted (don't ask). If both UNZIP and UNZIPOPT are defined, however, UNZIP takes precedence.

unzip's diagnostic option (-v with no zipfile name) can be

used to check the values of all four possible unzip and

zipinfo environment variables. The timezone variable (TZ) should be set according to the

local timezone in order for the -f and -u to operate

correctly. See the description of -f above for details.

This variable may also be necessary to get timestamps of extracted files to be set correctly. The WIN32

(Win9x/ME/NT4/2K/XP/2K3) port of unzip gets the timezone

configuration from the registry, assuming it is correctly set in the Control Panel. The TZ variable is ignored for this port. DECRYPTION

Encrypted archives are fully supported by Info-ZIP software,

but due to United States export restrictions, de-/encryption

support might be disabled in your compiled binary. However, since spring 2000, US export restrictions have been liberated, and our source archives do now include full crypt

code. In case you need binary distributions with crypt sup-

port enabled, see the file ``WHERE'' in any Info-ZIP source

or binary distribution for locations both inside and outside the US.

Some compiled versions of unzip may not support decryption.

To check a version for crypt support, either attempt to test

or extract an encrypted archive, or else check unzip's diag-

nostic screen (see the -v option above) for ``[decryption]''

as one of the special compilation options.

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Misc. Reference Manual Pages UNZIP(1L)

As noted above, the -P option may be used to supply a pass-

word on the command line, but at a cost in security. The preferred decryption method is simply to extract normally;

if a zipfile member is encrypted, unzip will prompt for the

password without echoing what is typed. unzip continues to

use the same password as long as it appears to be valid, by

testing a 12-byte header on each file. The correct password

will always check out against the header, but there is a 1-

in-256 chance that an incorrect password will as well.

(This is a security feature of the PKWARE zipfile format; it

helps prevent brute-force attacks that might otherwise gain

a large speed advantage by testing only the header.) In the case that an incorrect password is given but it passes the

header test anyway, either an incorrect CRC will be gen-

erated for the extracted data or else unzip will fail during

the extraction because the ``decrypted'' bytes do not con-

stitute a valid compressed data stream. If the first password fails the header check on some file,

unzip will prompt for another password, and so on until all

files are extracted. If a password is not known, entering a null password (that is, just a carriage return or ``Enter'') is taken as a signal to skip all further prompting. Only unencrypted files in the archive(s) will thereafter be extracted. (In fact, that's not quite true; older versions

of zip(1L) and zipcloak(1L) allowed null passwords, so unzip

checks each encrypted file to see if the null password

works. This may result in ``false positives'' and extrac-

tion errors, as noted above.)

Archives encrypted with 8-bit passwords (for example, pass-

words with accented European characters) may not be portable across systems and/or other archivers. This problem stems

from the use of multiple encoding methods for such charac-

ters, including Latin-1 (ISO 8859-1) and OEM code page 850.

DOS PKZIP 2.04g uses the OEM code page; Windows PKZIP 2.50

uses Latin-1 (and is therefore incompatible with DOS PKZIP);

Info-ZIP uses the OEM code page on DOS, OS/2 and Win3.x

ports but Latin-1 everywhere else; and Nico Mak's WinZip 6.x

does not allow 8-bit passwords at all. UnZip 5.3 (or newer)

attempts to use the default character set first (e.g.,

Latin-1), followed by the alternate one (e.g., OEM code

page) to test passwords. On EBCDIC systems, if both of these fail, EBCDIC encoding will be tested as a last resort.

(EBCDIC is not tested on non-EBCDIC systems, because there

are no known archivers that encrypt using EBCDIC encoding.)

ISO character encodings other than Latin-1 are not sup-

ported.

EXAMPLES

To use unzip to extract all members of the archive

letters.zip into the current directory and subdirectories

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Misc. Reference Manual Pages UNZIP(1L) below it, creating any subdirectories as necessary:

unzip letters

To extract all members of letters.zip into the current directory only:

unzip -j letters

To test letters.zip, printing only a summary message indi-

cating whether the archive is OK or not:

unzip -tq letters

To test all zipfiles in the current directory, printing only the summaries:

unzip -tq \*.zip

(The backslash before the asterisk is only required if the shell expands wildcards, as in Unix; double quotes could have been used instead, as in the source examples below.) To extract to standard output all members of

letters.zip whose names end in .tex, auto-converting to the

local end-of-line convention and piping the output into

more(1):

unzip -ca letters \*.tex | more

To extract the binary file paper1.dvi to standard output and pipe it to a printing program:

unzip -p articles paper1.dvi | dvips

To extract all FORTRAN and C source files--*.f, *.c, *.h,

and Makefile--into the /tmp directory:

unzip source.zip "*.[fch]" Makefile -d /tmp

(the double quotes are necessary only in Unix and only if globbing is turned on). To extract all FORTRAN and C source files, regardless of case (e.g., both *.c and *.C, and any makefile, Makefile, MAKEFILE or similar):

unzip -C source.zip "*.[fch]" makefile -d /tmp

To extract any such files but convert any uppercase MS-DOS

or VMS names to lowercase and convert the line-endings of

all of the files to the local standard (without respect to any files that might be marked ``binary''):

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Misc. Reference Manual Pages UNZIP(1L)

unzip -aaCL source.zip "*.[fch]" makefile -d /tmp

To extract only newer versions of the files already in the current directory, without querying (NOTE: be careful of

unzipping in one timezone a zipfile created in another--ZIP

archives other than those created by Zip 2.1 or later con-

tain no timezone information, and a ``newer'' file from an eastern timezone may, in fact, be older):

unzip -fo sources

To extract newer versions of the files already in the current directory and to create any files not already there (same caveat as previous example):

unzip -uo sources

To display a diagnostic screen showing which unzip and

zipinfo options are stored in environment variables, whether decryption support was compiled in, the compiler with which

unzip was compiled, etc.:

unzip -v

In the last five examples, assume that UNZIP or UNZIP_OPTS

is set to -q. To do a singly quiet listing:

unzip -l file.zip

To do a doubly quiet listing:

unzip -ql file.zip

(Note that the ``.zip'' is generally not necessary.) To do a standard listing:

unzip --ql file.zip

unzip -l-q file.zip

unzip -l--q file.zip

(Extra minuses in options don't hurt.) TIPS The current maintainer, being a lazy sort, finds it very

useful to define a pair of aliases: tt for ``unzip -tq''

and ii for ``unzip -Z'' (or ``zipinfo''). One may then sim-

ply type ``tt zipfile'' to test an archive, something that

is worth making a habit of doing. With luck unzip will

report ``No errors detected in compressed data of zipfile.zip,'' after which one may breathe a sigh of relief.

Info-ZIP Last change: 28 December 2007 (v5.53) 15

Misc. Reference Manual Pages UNZIP(1L) The maintainer also finds it useful to set the UNZIP

environment variable to ``-aL'' and is tempted to add ``-C''

as well. His ZIPINFO variable is set to ``-z''.

DIAGNOSTICS The exit status (or error level) approximates the exit codes defined by PKWARE and takes on the following values, except under VMS: 0 normal; no errors or warnings detected. 1 one or more warning errors were encountered, but processing completed successfully anyway. This includes zipfiles where one or more files was skipped due to unsupported compression method or encryption with an unknown password. 2 a generic error in the zipfile format was

detected. Processing may have completed success-

fully anyway; some broken zipfiles created by

other archivers have simple work-arounds.

3 a severe error in the zipfile format was detected. Processing probably failed immediately.

4 unzip was unable to allocate memory for one or

more buffers during program initialization.

5 unzip was unable to allocate memory or unable to

obtain a tty to read the decryption password(s).

6 unzip was unable to allocate memory during

decompression to disk.

7 unzip was unable to allocate memory during in-

memory decompression. 8 [currently not used] 9 the specified zipfiles were not found. 10 invalid options were specified on the command line. 11 no matching files were found. 50 the disk is (or was) full during extraction.

51 the end of the ZIP archive was encountered prema-

turely.

80 the user aborted unzip prematurely with control-C

Info-ZIP Last change: 28 December 2007 (v5.53) 16

Misc. Reference Manual Pages UNZIP(1L) (or similar) 81 testing or extraction of one or more files failed

due to unsupported compression methods or unsup-

ported decryption. 82 no files were found due to bad decryption password(s). (If even one file is successfully processed, however, the exit status is 1.) VMS interprets standard Unix (or PC) return values as other,

scarier-looking things, so unzip instead maps them into

VMS-style status codes. The current mapping is as follows:

1 (success) for normal exit, 0x7fff0001 for warning errors,

and (0x7fff000? + 16*normal_unzip_exit_status) for all other

errors, where the `?' is 2 (error) for unzip values 2, 9-11

and 80-82, and 4 (fatal error) for the remaining ones (3-8,

50, 51). In addition, there is a compilation option to

expand upon this behavior: defining RETURN_CODES results in

a human-readable explanation of what the error status means.

BUGS

Multi-part archives are not yet supported, except in con-

junction with zip. (All parts must be concatenated together

in order, and then ``zip -F'' must be performed on the con-

catenated archive in order to ``fix'' it.) This will defin-

itely be corrected in the next major release. Archives read from standard input are not yet supported,

except with funzip (and then only the first member of the

archive can be extracted).

Archives encrypted with 8-bit passwords (e.g., passwords

with accented European characters) may not be portable across systems and/or other archivers. See the discussion in DECRYPTION above.

unzip's -M (``more'') option tries to take into account

automatic wrapping of long lines. However, the code may fail

to detect the correct wrapping locations. First, TAB charac-

ters (and similar control sequences) are not taken into account, they are handled as ordinary printable characters.

Second, depending on the actual system / OS port, unzip may

not detect the true screen geometry but rather rely on "com-

monly used" default dimensions. The correct handling of tabs would require the implementation of a query for the actual tabulator setup on the output console. Dates, times and permissions of stored directories are not restored except under Unix. (On Windows NT and successors, timestamps are now restored.)

Info-ZIP Last change: 28 December 2007 (v5.53) 17

Misc. Reference Manual Pages UNZIP(1L)

[MS-DOS] When extracting or testing files from an archive on

a defective floppy diskette, if the ``Fail'' option is chosen from DOS's ``Abort, Retry, Fail?'' message, older

versions of unzip may hang the system, requiring a reboot.

This problem appears to be fixed, but control-C (or

control-Break) can still be used to terminate unzip.

Under DEC Ultrix, unzip would sometimes fail on long zip-

files (bad CRC, not always reproducible). This was apparently due either to a hardware bug (cache memory) or an operating system bug (improper handling of page faults?). Since Ultrix has been abandoned in favor of Digital Unix (OSF/1), this may not be an issue anymore. [Unix] Unix special files such as FIFO buffers (named pipes), block devices and character devices are not restored even if they are somehow represented in the zipfile, nor are

hard-linked files relinked. Basically the only file types

restored by unzip are regular files, directories and sym-

bolic (soft) links. [OS/2] Extended attributes for existing directories are only

updated if the -o (``overwrite all'') option is given. This

is a limitation of the operating system; because directories

only have a creation time associated with them, unzip has no

way to determine whether the stored attributes are newer or

older than those on disk. In practice this may mean a two-

pass approach is required: first unpack the archive nor-

mally (with or without freshening/updating existing files),

then overwrite just the directory entries (e.g., ``unzip -o

foo */''). [VMS] When extracting to another directory, only the [.foo]

syntax is accepted for the -d option; the simple Unix foo

syntax is silently ignored (as is the less common VMS foo.dir syntax).

[VMS] When the file being extracted already exists, unzip's

query only allows skipping, overwriting or renaming; there should additionally be a choice for creating a new version of the file. In fact, the ``overwrite'' choice does create a new version; the old version is not overwritten or deleted.

funzip(1L), zip(1L), zipcloak(1L), zipgrep(1L), zipinfo(1L),

zipnote(1L), zipsplit(1L) URL

The Info-ZIP home page is currently at

http://www.info-zip.org/pub/infozip/

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Misc. Reference Manual Pages UNZIP(1L)

ftp://ftp.info-zip.org/pub/infozip/ .

AUTHORS

The primary Info-ZIP authors (current semi-active members of

the Zip-Bugs workgroup) are: Ed Gordon (Zip, general

maintenance, shared code, Zip64, Win32, Unix); Christian

Spieler (UnZip maintenance coordination, VMS, MS-DOS, Win32,

shared code, general Zip and UnZip integration and optimiza-

tion); Onno van der Linden (Zip); Mike White (Win32, Windows GUI, Windows DLLs); Kai Uwe Rommel (OS/2, Win32); Steven M. Schweda (VMS, support of new features); Paul Kienitz (Amiga, Win32); Chris Herborth (BeOS, QNX, Atari); Jonathan Hudson

(SMS/QDOS); Sergio Monesi (Acorn RISC OS); Harald Denker (Atari, MVS); John Bush (Solaris, Amiga); Hunter Goatley

(VMS, Info-ZIP Site maintenance); Steve Salisbury (Win32);

Steve Miller (Windows CE GUI), Johnny Lee (MS-DOS, Win32,

Zip64); and Dave Smith (Tandem NSK).

The following people were former members of the Info-ZIP

development group and provided major contributions to key parts of the current code: Greg ``Cave Newt'' Roelofs

(UnZip, unshrink decompression); Jean-loup Gailly (deflate

compression); Mark Adler (inflate decompression, fUnZip).

The author of the original unzip code upon which Info-ZIP's

was based is Samuel H. Smith; Carl Mascott did the first

Unix port; and David P. Kirschbaum organized and led Info-

ZIP in its early days with Keith Petersen hosting the origi-

nal mailing list at WSMR-SimTel20. The full list of contri-

butors to UnZip has grown quite large; please refer to the

CONTRIBS file in the UnZip source distribution for a rela-

tively complete version. VERSIONS v1.2 15 Mar 89 Samuel H. Smith v2.0 9 Sep 89 Samuel H. Smith v2.x fall 1989 many Usenet contributors

v3.0 1 May 90 Info-ZIP (DPK, consolidator)

v3.1 15 Aug 90 Info-ZIP (DPK, consolidator)

v4.0 1 Dec 90 Info-ZIP (GRR, maintainer)

v4.1 12 May 91 Info-ZIP

v4.2 20 Mar 92 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.0 21 Aug 92 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.01 15 Jan 93 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.1 7 Feb 94 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.11 2 Aug 94 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.12 28 Aug 94 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.2 30 Apr 96 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.3 22 Apr 97 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.31 31 May 97 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.32 3 Nov 97 Info-ZIP (Zip-Bugs subgroup, GRR)

v5.4 28 Nov 98 Info-ZIP (Zip-Bugs subgroup, SPC)

Info-ZIP Last change: 28 December 2007 (v5.53) 19

Misc. Reference Manual Pages UNZIP(1L)

v5.41 16 Apr 00 Info-ZIP (Zip-Bugs subgroup, SPC)

v5.42 14 Jan 01 Info-ZIP (Zip-Bugs subgroup, SPC)

v5.5 17 Feb 02 Info-ZIP (Zip-Bugs subgroup, SPC)

v5.51 22 May 04 Info-ZIP (Zip-Bugs subgroup, SPC)

v5.52 28 Feb 05 Info-ZIP (Zip-Bugs subgroup, SPC)

v5.53 28 Dec 07 Info-ZIP (Zip-Bugs subgroup, SPC)

ATTRIBUTES

See attributes(5) for descriptions of the following attri-

butes:

_______________________________________

| ATTRIBUTE TYPE | ATTRIBUTE VALUE|

|____________________|__________________|_

| Availability | compress/unzip |

|____________________|__________________|_

| Interface Stability| External |

|____________________|_________________|

NOTES

Source for unzip is available on http://opensolaris.org.

Info-ZIP Last change: 28 December 2007 (v5.53) 20