Content
Data
Version: 6.00
Developer / Owner: Info-ZIP
Short description:
The manual page and help for the unzip linux command. The unzip linux command lists, tests, or extracts files from the ZIP archive. The default operation without the option is to extract the files to the current directory (along with its subdirectories) from the specified zip file.
Man page output
man unzipUNZIP(1) General Commands Manual UNZIP(1)
NAME
unzip - list, test and extract compressed files in a ZIP archive
SYNOPSIS
unzip [-Z] [-cflptTuvz[abjnoqsCDKLMUVWX$/:^]] 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(1), 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 system). 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 char‐
acter. If an exclamation point or a caret (`!' or `^') follows
the left bracket, then the range of characters 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, particularly under Unix and VMS.) If
no matches are found, the specification is assumed to be a literal file‐
name; and if that also fails, the suffix .zip is appended. Note that
self-extracting ZIP files are supported, as with any other ZIP archive;
just specify the .exe suffix (if any) explicitly.
[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 (wildcards) 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
system.
[-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
directories 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 specifi‐
cation (with the normal options), immediately after the zipfile specifi‐
cation, or between the file(s) and the -x option. The option and direc‐
tory may be concatenated without any white space between them, but note
that this may cause normal shell behavior to be suppressed. In particu‐
lar, ``-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 therefore 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(1) mode. If the first option on the command line is -Z, the
remaining options are taken to be zipinfo(1) options. See the appropri‐
ate manual page for a description of these options.
-A [OS/2, Unix DLL] print extended help for the DLL's 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 auto‐
matically 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 overwriting, but the -o option may be used to suppress the
queries. Note that under many operating systems, the TZ (timezone) envi‐
ronment 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 typical TZ
value is ``PST8PDT'' (US Pacific time with automatic adjustment for Day‐
light 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 specified file in memory
and compares the CRC (cyclic redundancy 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 zipfiles (e.g., ``unzip -T \*.zip'') and is much
faster.
-u update existing files and create new ones if needed. This option per‐
forms 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 com‐
pressed size numbers. Therefore, compressed size and compression ratio
figures are independent of the entry's encryption status and show the
correct compression performance. (The complete size of the encrypted
compressed data stream for zipfile entries is reported by the more ver‐
bose zipinfo(1) reports, see the separate manual.) When no zipfile is
specified (that is, the complete command is simply ``unzip -v''), a diag‐
nostic screen is printed. In addition to the normal 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 system
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 vari‐
ables that might do the same (see ENVIRONMENT OPTIONS below). As a modi‐
fier 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, converting line
endings, end-of-file characters and the character set itself as neces‐
sary. (For example, Unix files use line feeds (LFs) for end-of-line
(EOL) and have no end-of-file (EOF) marker; Macintoshes use carriage
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 Ter‐
minal System use EBCDIC rather than the more common ASCII character 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 vis‐
ual 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 sup‐
posed file type. On VMS, see also -S.
-b [general] treat all files as binary (no text conversions). 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 [when compiled with UNIXBACKUP defined] save a backup copy of each over‐
written file. The backup file is gets the name of the target file with a
tilde and optionally a unique sequence number (up to 5 digits) appended.
The sequence number is applied whenever another file with the original
name plus tilde already exists. When used together with the "overwrite
all" option -o, numbered backup files are never created. In this case,
all backup files are named as the original file with an appended tilde,
existing backup files are deleted without notice. This feature works
similarly to the default behavior of emacs(1) in many locations.
Example: the old copy of ``foo'' is renamed to ``foo~''.
Warning: Users should be aware that the -B option does not prevent loss
of existing data under all circumstances. For example, when unzip is run
in overwrite-all mode, an existing ``foo~'' file is deleted before unzip
attempts to rename ``foo'' to ``foo~''. When this rename attempt fails
(because of a file locks, insufficient privileges, or ...), the extrac‐
tion of ``foo~'' gets cancelled, but the old backup file is already lost.
A similar scenario takes place when the sequence number range for num‐
bered backup files gets exhausted (99999, or 65535 for 16-bit systems).
In this case, the backup file with the maximum sequence number is deleted
and replaced by the new backup version without notice.
-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 platforms,
unzip's default behavior is to match both wildcard and literal filenames
case-sensitively. That is, specifying ``makefile'' on the command line
will only match ``makefile'' in the archive, not ``Makefile'' or ``MAKE‐
FILE'' (and similarly for wildcard specifications). Since this does not
correspond to the behavior of many other operating/file systems (for
example, OS/2 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 sup‐
plied in the Zip archive (and do not require privileges or impose a secu‐
rity 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 timestamps are restored, timestamps of
extracted directories are left at the current time. To enable restora‐
tion of directory timestamps, the negated option --D should be specified.
On VMS, the option -D disables timestamp restoration for all extracted
Zip archive items. (Here, a single -D on the command line combines with
the default -D to do what an explicit -DD does on other systems.)
-E [MacOS only] display contents of MacOS extra field during restore opera‐
tion.
-F [Acorn only] suppress removal of NFS filetype extension from stored file‐
names.
-F [non-Acorn systems supporting long filenames with embedded commas, and
only if compiled with ACORN_FTYPE_NFS defined] translate filetype infor‐
mation from ACORN RISC OS extra field blocks into a NFS filetype exten‐
sion 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 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. With‐
out this flag, these attribute bits are cleared for security reasons.
-L convert to lowercase any filename originating on an uppercase-only oper‐
ating 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 sin‐
gle-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 unsup‐
ported characters, etc.); this option causes the names of all files from
certain systems to be converted to lowercase. The -LL option forces con‐
version 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, effec‐
tively 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.
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 cre‐
ated with the -c option of zip(1), or with the -N option of the Amiga
port of zip(1), 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 sys‐
tems 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). Ordinarily unzip prints
the names of the files it's extracting or testing, the extraction meth‐
ods, 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 awk‐
ward, however, since MS-DOS in particular does not gracefully support
spaces in filenames. Conversion of spaces to underscores can eliminate
the awkwardness in some cases.
-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 pro‐
cessed.)
-U [UNICODE_SUPPORT only] modify or disable UTF-8 handling. When UNI‐
CODE_SUPPORT is available, the option -U forces unzip to escape all non-
ASCII characters from UTF-8 coded filenames as ``#Uxxxx'' (for UCS-2
characters, or ``#Lxxxxxx'' for unicode codepoints needing 3 octets).
This option is mainly provided for debugging purpose when the fairly new
UTF-8 support is suspected to mangle up extracted filenames.
The option -UU allows to entirely disable the recognition of UTF-8
encoded filenames. The handling of filename codings within unzip falls
back to the behaviour of previous versions.
[old, obsolete usage] 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 ver‐
sion 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 ver‐
sion 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 character `/'.
(The two-character sequence ``**'' acts as a multi-char wildcard that
includes the directory separator 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 pattern matching rules for both wildcard zipfile
specifications and zip entry selection patterns in most ports. For sys‐
tems allowing `/' as regular filename character, the -W option would not
work as expected on a wildcard zipfile specification.)
-X [VMS, Unix, OS/2, NT, Tandem] restore owner/protection info (UICs and ACL
entries) under VMS, or user and group info (UID/GID) under Unix, or
access control lists (ACLs) under certain 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 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 available on some
operating systems. [NT's access control lists do not appear to be espe‐
cially compatible with OS/2's, so no attempt is made at cross-platform
portability of access privileges. It is not clear under what conditions
this would ever be useful anyway.]
-Y [VMS] treat archived file name endings of ``.nnn'' (where ``nnn'' is a
decimal number) as if they were VMS version numbers (``;nnn''). (The
default is to treat them as file types.) Example:
"a.b.3" -> "a.b;3".
-$ [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 environ‐
ment 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 ``sensi‐
tive'' 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 multiple directory trees at the level of the current extraction
folder. This option does not enable writing explicitly to the root
directory (``/''). To achieve this, it is necessary to set the extrac‐
tion 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 C
string termination indicator), unless the specific file system has more
restrictive conventions. Generally, this allows to embed ASCII control
characters (or even sophisticated control sequences) in file names, at
least on 'native' Unix file systems. However, it may be highly suspi‐
cious 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 filtering. 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). Therefore, unzip applies
a filter by default that removes potentially dangerous control characters
from the extracted file names. The -^ option allows to override this fil‐
ter in the rare case that embedded filename control characters are to be
intentionally restored.
-2 [VMS] force unconditionally conversion of file names to ODS2-compatible
names. The default is to exploit the destination file system, preserving
case and extended file name characters on an ODS5 destination file sys‐
tem; and applying the ODS2-compatibility file name filtering on an ODS2
destination file system.
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 com‐
mand-line options, except that they are effectively the first options on the
command line. To override 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
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 quiet‐
ness. To cancel 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 confusing, but it is reason‐
ably 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 oth‐
erwise be confused with the environment variable), and UNZIP for all other oper‐
ating systems. For compatibility with zip(1), 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 support 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 diagnostic screen (see the -v option above) for ``[decryp‐
tion]'' as one of the special compilation options.
As noted above, the -P option may be used to supply a password 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 pass‐
word 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 secu‐
rity 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 generated for the extracted data or else
unzip will fail during the extraction because the ``decrypted'' bytes do not
constitute 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(1) and zipcloak(1) allowed null passwords, so unzip checks
each encrypted file to see if the null password works. This may result in
``false positives'' and extraction errors, as noted above.)
Archives encrypted with 8-bit passwords (for example, passwords 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 incom‐
patible with DOS PKZIP); Info-ZIP uses the OEM code page on DOS, OS/2 and Win3.x
ports but ISO coding (Latin-1 etc.) 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 supported.
The new addition of (partially) Unicode (resp. UTF-8) support in UnZip 6.0 has
not yet been adapted to the encryption password handling in unzip. On systems
that use UTF-8 as native character encoding, unzip simply tries decryption with
the native UTF-8 encoded password; the built-in attempts to check the password
in translated encoding have not yet been adapted for UTF-8 support and will con‐
sequently fail.
EXAMPLES
To use unzip to extract all members of the archive letters.zip into the current
directory and subdirectories 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 indicating whether the ar‐
chive 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 wild‐
cards, 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 pip‐
ing 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 print‐
ing 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 low‐
ercase and convert the line-endings of all of the files to the local standard
(without respect to any files that might be marked ``binary''):
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 cre‐
ated 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
or
unzip -l-q file.zip
or
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 simply 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.
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 com‐
pleted 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 successfully anyway; some broken zipfiles cre‐
ated 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 decompres‐
sion.
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 prematurely.
80 the user aborted unzip prematurely with control-C (or similar)
81 testing or extraction of one or more files failed due to unsup‐
ported compression methods or unsupported 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 compila‐
tion 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 conjunction with zip. (All
parts must be concatenated together in order, and then ``zip -F'' (for zip 2.x)
or ``zip -FF'' (for zip 3.x) must be performed on the concatenated archive in
order to ``fix'' it. Also, zip 3.0 and later can combine multi-part (split) ar‐
chives into a combined single-file archive using ``zip -s- inarchive -O out‐
archive''. See the zip 3 manual page for more information.) This will defi‐
nitely 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 characters (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 "commonly 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.)
[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 zipfiles (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 symbolic (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 sys‐
tem; 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 normally (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 cre‐
ate a new version; the old version is not overwritten or deleted.
SEE ALSO
funzip(1), zip(1), zipcloak(1), zipgrep(1), zipinfo(1), zipnote(1), zipsplit(1)
URL
The Info-ZIP home page is currently at
http://www.info-zip.org/pub/infozip/
or
ftp://ftp.info-zip.org/pub/infozip/ .
AUTHORS
The primary Info-ZIP authors (current semi-active members of the Zip-Bugs work‐
group) are: Ed Gordon (Zip, general maintenance, shared code, Zip64, Win32,
Unix, Unicode); Christian Spieler (UnZip maintenance coordination, VMS, MS-DOS,
Win32, shared code, general Zip and UnZip integration and optimization); Onno
van der Linden (Zip); Mike White (Win32, Windows GUI, Windows DLLs); Kai Uwe
Rommel (OS/2, Win32); Steven M. Schweda (VMS, Unix, support of new features);
Paul Kienitz (Amiga, Win32, Unicode); 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 mainte‐
nance); 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 com‐
pression); 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 orga‐
nized and led Info-ZIP in its early days with Keith Petersen hosting the origi‐
nal mailing list at WSMR-SimTel20. The full list of contributors to UnZip has
grown quite large; please refer to the CONTRIBS file in the UnZip source distri‐
bution for a relatively 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)
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)
v6.0 20 Apr 09 Info-ZIP (Zip-Bugs subgroup, SPC)
Info-ZIP 20 April 2009 (v6.0) UNZIP(1)
Help output
unzip --helpUnZip 6.00 of 20 April 2009, by Debian. Original by Info-ZIP.
Usage: unzip [-Z] [-opts[modifiers]] file[.zip] [list] [-x xlist] [-d exdir]
Default action is to extract files in list, except those in xlist, to exdir;
file[.zip] may be a wildcard. -Z => ZipInfo mode ("unzip -Z" for usage).
-p extract files to pipe, no messages -l list files (short format)
-f freshen existing files, create none -t test compressed archive data
-u update files, create if necessary -z display archive comment only
-v list verbosely/show version info -T timestamp archive to latest
-x exclude files that follow (in xlist) -d extract files into exdir
modifiers:
-n never overwrite existing files -q quiet mode (-qq => quieter)
-o overwrite files WITHOUT prompting -a auto-convert any text files
-j junk paths (do not make directories) -aa treat ALL files as text
-U use escapes for all non-ASCII Unicode -UU ignore any Unicode fields
-C match filenames case-insensitively -L make (some) names lowercase
-X restore UID/GID info -V retain VMS version numbers
-K keep setuid/setgid/tacky permissions -M pipe through "more" pager
See "unzip -hh" or unzip.txt for more help. Examples:
unzip data1 -x joe => extract all files except joe from zipfile data1.zip
unzip -p foo | more => send contents of foo.zip via pipe into program more
unzip -fo foo ReadMe => quietly replace existing ReadMe if archive file newer
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