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UNZIP(1L) UNZIP(1L)
NAME
unzip - list, test and extract compressed files in a ZIP archive
SYNOPSIS
unzip [-Z] [-cflptuvz[abjnoqsCLMVX$/:]] 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 cre-
ated 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 deter-
mined by the operating system (or file system). Only the file-
name 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).
(Be sure to quote any character that might otherwise be inter-
preted or modified by the operating system, 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 sys-
tem.
[-x xfile(s)]
An optional list of archive members to be excluded from pro-
cessing. Since wildcard characters match directory separators
('/'), 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 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 speci-
fication, 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 behav-
ior 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 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(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 programming
interface (API).
-c extract files to stdout/screen (''CRT''). This option is simi-
lar 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 appropri-
ate. 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 differ-
ences between DOS-format file times (always local time) and
Unix-format times (always in GMT/UTC) and the necessity to com-
pare 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 comments (if any) are dis-
played. 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 pre-
fixed 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 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 be verbose or print 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. 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 variables that might do the same (see ENVIRON-
MENT OPTIONS below). As a modifier it works in conjunction
with other options (e.g., -t) to produce more verbose or debug-
ging 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 charac-
ters and the 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 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 Terminal 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 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.
-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 stan-
dard 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 loca-
tions.
-C match filenames case-insensitively. 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-sensi-
tively. That is, specifying ''makefile'' on the command line
will only match ''makefile'' in the archive, not ''Makefile''
or ''MAKEFILE'' (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 ''make-
file'' (or ''make*'', or similar). The -C option affects files
in both the normal file list and the excluded-file list
(xlist).
-E [MacOS only] display contents of MacOS extra field during
restore operation.
-F [Acorn only] suppress removal of NFS filetype extension from
stored filenames.
-F [non-Acorn systems supporting long filenames with embedded com-
mas, and only if compiled with ACORN_FTYPE_NFS defined] trans-
late 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 recre-
ated; 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.
-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 extract-
ing 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 (except-
ing truncation, conversion of unsupported characters, etc.);
this option causes the names of all files from certain systems
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. 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, over-
write 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 com-
ments 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 danger-
ous 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 utili-
ties.)
-q perform operations quietly (-qq = even quieter). Ordinarily
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 particular does not gracefully support spaces in filenames.
Conversion of spaces to underscores can eliminate the awkward-
ness in some cases.
-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 file-
names to particularly short lengths, the version numbers may be
truncated or stripped regardless of this option.)
-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 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 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 especially 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.]
-$ [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 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 specifiying enough ''../'' path components within
the zip file. Use this option with extreme caution.
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 file-
names 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 override an environment option, one
may use the ''minus operator'' to remove it. For instance, to over-
ride 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 quietness. 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 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 for-
eign command would otherwise be confused with the environment vari-
able), 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 time-
zone in order for the -f and -u to operate correctly. See the
description of -f above for details. This variable may also be neces-
sary in order for timestamps on extracted files to be set correctly.
Under Windows 95/NT unzip should know the correct timezone even if TZ
is unset, assuming the timezone is correctly set in the Control Panel.
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 ''[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
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 generated for the extracted data or else unzip will fail dur-
ing 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(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 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; Win-
dows 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 supported.
EXAMPLES
To use unzip to extract all members of the archive letters.zip into
the current directory and subdirectories below it, creating any subdi-
rectories 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 archive is OK or not:
unzip -tq letters
To test all zipfiles in the current directory, printing only the sum-
maries:
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-con-
verting 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 Make-
file--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''):
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 direc-
tory and to create any files not already there (same caveat as previ-
ous 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 vari-
able 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 pro-
cessing 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. Pro-
cessing 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 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.
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*nor-
mal_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 conjunction with
zip. (All parts must be concatenated together in order, and then
''zip -F'' must be performed on the concatenated archive in order to
''fix'' it.) 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 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 cor-
rect 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 defec-
tive 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 han-
dling 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 some-
how 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 renaming; there should additionally be
a choice for creating a new version of the file. In fact, the ''over-
write'' choice does create a new version; the old version is not over-
written or deleted.
SEE ALSO
funzip(1L), zip(1L), zipcloak(1L), zipgrep(1L), zipinfo(1L), zip-
note(1L), zipsplit(1L)
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 workgroup) are: Onno van der Linden (Zip); Christian Spieler
(UnZip maintenance coordination, VMS, MS-DOS, Win32, shared code, gen-
eral Zip and UnZip integration and optimization); Mike White (Windows
GUI, Windows DLLs); Kai Uwe Rommel (OS/2); 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); Steve Salisbury (Win32); Steve
Miller (Windows CE GUI), Johnny Lee (MS-DOS, Win32); 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 decompres-
sion, 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)
Info-ZIP 22 May 2004 (v5.51) UNZIP(1L)
UNIX/Linux commands referenced on this page: