UNZIP(1L) UNZIP(1L)
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(1L), creates ZIP archives; both programs are compat‐
ible 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 character. 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 sys‐
tem, particularly 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 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 recre‐
ated in the current directory; the -d option allows extraction in an arbitrary directory (always assum‐
ing one has permission to write to the directory). This option need not appear at the end of the com‐
mand line; it is also accepted before the zipfile specification (with the normal options), immediately
after the zipfile specification, 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
-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
automatically 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) 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 typical 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 com‐
ments (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 corre‐
sponds 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 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 speci‐
fied with no other options, -v lists archive files verbosely, adding to the basic -l info the compres‐
sion 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 compression 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 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 com‐
piled, 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 conjunc‐
tion 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.
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 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 overwritten 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 cir‐
cumstances. 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 extraction of ``foo~'' gets cancelled, but the old backup
file is already lost. A similar scenario takes place when the sequence number range for numbered
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 responsi‐
ble 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 ``MAKEFILE'' (and similarly for wildcard specifica‐
tions). Since this does not correspond to the behavior of many other operating/file systems (for exam‐
ple, 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-informa‐
tion for extracted items that are supplied in the Zip archive (and do not require privileges or impose
a security risk). By specifying -D, unzip is told to suppress restoration of timestamps for directo‐
ries explicitly created from Zip archive entries. This option only applies to ports that support set‐
ting timestamps for directories (currently ATheOS, BeOS, MacOS, OS/2, Unix, VMS, Win32, for other unzip
-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 filetype 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 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 extrac‐
tion 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-pre‐
serving 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 con‐
verted 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 screen‐
ful 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. 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.)
ing 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 particular does not gracefully support spaces in file‐
names. 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 processed.)
-U [UNICODE_SUPPORT only] modify or disable UTF-8 handling. When UNICODE_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 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
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 sys‐
tems 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 systems allowing
`/' as regular filename character, the -W option would not work as expected on a wildcard zipfile spec‐
ification.)
-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 ver‐
sions 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 dou‐
bling 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 especially compatible with OS/2's, so no attempt is made at
[Acorn only] overrides the extension list supplied by Unzip$Ext environment variable. During extrac‐
tion, 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) pre‐
vents 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 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 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 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 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 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 filter 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 des‐
tination file system; 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-con‐
vert 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 follow‐
ing 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
(the two are equivalent). This may seem awkward or confusing, 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 confused 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 time‐
stamps 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 dis‐
tribution 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 ``[decryption]'' 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 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 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 ar‐
chive(s) will thereafter be extracted. (In fact, that's not quite true; older versions of zip(1L) and zip‐
cloak(1L) 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 characters, 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 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 sys‐
tems, 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
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 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-end‐
ings 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 created in another--ZIP archives other than those created by
Zip 2.1 or later contain 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
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 com‐
pressed 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 val‐
ues, 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 successfully
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 pass‐
word(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 prematurely.
80 the user aborted unzip prematurely with control-C (or similar)
81 testing or extraction of one or more files failed due to unsupported compression methods or
unsupported decryption.
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) archives
into a combined single-file archive using ``zip -s- inarchive -O outarchive''. See the zip 3 manual page for
more information.) This will definitely 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 porta‐
ble 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 suc‐
cessors, 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 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 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 renam‐
ing; 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.
SEE ALSO
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/
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 original 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 distribution 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(1L)
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