UNZIP(1L)UNZIP(1L)NAMEunzip - list, test and extract compressed files in a ZIP archive
SYNOPSISunzip [-Z] [-cflptuvz[abjnoqsCLMVX$/]] file[.zip] [file(s) ...]
[-xxfile(s) ...] [-d exdir]
DESCRIPTIONunzip 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 determined
by the operating system (or file system). Only the filename can
be a wildcard; the path itself cannot. Wildcard expressions are
similar to Unix egrep(1) (regular) expressions 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 system.
[-xxfile(s)]
An optional list of archive members to be excluded from process‐
ing. 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 direc‐
tory; 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 command line; it
is also accepted before the zipfile specification (with the nor‐
mal 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 of the user's home directory, but ``-d~'' is
treated as a literal subdirectory ``~'' of the current direc‐
tory.
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:
-Zzipinfo(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 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 oper‐
ating 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-for‐
mat 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 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, compres‐
sion ratio and 32-bit CRC. 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 compiled, the compiler
and version used, and the compilation date; any special compila‐
tion 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 modifier it works in conjunction with other options (e.g.,
-t) to produce more verbose or debugging output; this is not yet
fully implemented but will be in future releases.
-z display only the archive comment.
MODIFIERS-a convert text files. Ordinarily all files are extracted exactly
as they are stored (as ``binary'' files). The -a option causes
files identified by zip as text files (those with the `t' label
in zipinfo listings, rather than `b') to be automatically
extracted as such, 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.
-B [Unix only, and only if compiled with UNIXBACKUP defined] save a
backup copy of each overwritten file with a tilde appended
(e.g., the old copy of ``foo'' is renamed to ``foo~''). This is
similar to the default behavior of emacs(1) in many locations.
-C 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 sys‐
tems 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 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 [Unix only, 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 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 extracting to a
case-preserving file system such as OS/2 HPFS or a case-sensi‐
tive one such as under Unix. By default unzip lists and
extracts such filenames exactly as they're stored (excepting
truncation, conversion of unsupported characters, etc.); this
option causes the names of all files from certain systems to be
converted to lowercase.
-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 likeli‐
hood 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 com‐
ments.
-o overwrite existing files without prompting. This is a dangerous
option, so use it with care. (It is often used with -f, how‐
ever, 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 sys‐
tems 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. Stor‐
ing 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 pass‐
words. (And where security is truly important, use
strong encryption such as Pretty Good Privacy instead of
the relatively weak encryption provided by standard zip‐
file utilities.)
-q perform operations quietly (-qq = even quieter). Ordi‐
narily unzip prints the names of the files it's extract‐
ing or testing, the extraction methods, any file or zip‐
file comments that may be stored in the archive, and pos‐
sibly 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 under‐
scores. Since all PC operating systems allow spaces in
filenames, unzip by default extracts filenames with spa‐
ces 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 awkwardness in some cases.
-U (obsolete; to be removed in a future release) leave file‐
names 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.)
-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 net‐
work-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 privi‐
leges 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). Dou‐
bling 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 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.
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 over‐
write 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 com‐
mands:
UNZIP=-qq; export UNZIP Unix Bourne shell
setenv UNZIP -qq Unix C shell
set UNZIP=-qq OS/2 or MS-DOS
define UNZIP_OPTS "-qq" VMS (quotes for lowercase)
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 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 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 con‐
fusing, 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 zip‐
file 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 cor‐
rectly. See the description of -f above for details.
This variable may also be necessary in order for time‐
stamps 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 soft‐
ware, but due to United States export restrictions,
de-/encryption support might be disabled in your compiled
binary. However, since spring 2000, US export restric‐
tions have been liberated, and our source archives do now
include full crypt code. In case you need binary distri‐
butions 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 decryp‐
tion. 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 nor‐
mally; 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 incor‐
rect 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 during the
extraction because the ``decrypted'' bytes do not consti‐
tute 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 Latin-1 everywhere
else; and Nico Mak's WinZip 6.x does not allow 8-bit
passwords at all. UnZip 5.3 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. (Since there are no
known archivers that encrypt using EBCDIC encoding,
EBCDIC is not tested on non-EBCDIC systems.) ISO charac‐
ter encodings other than Latin-1 are not supported.
EXAMPLES
To use unzip to extract all members of the archive let‐
ters.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 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 care‐
ful 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
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 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 val‐
ues, except under VMS:
0 normal; no errors or warnings detected.
1 one or more warning errors were encoun‐
tered, but processing completed success‐
fully anyway. This includes zipfiles where
one or more files was skipped due to unsup‐
ported 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 imme‐
diately.
4 unzip was unable to allocate memory for one
or more buffers during program initializa‐
tion.
5 unzip was unable to allocate memory or
unable to obtain a tty to read the decryp‐
tion 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 com‐
mand line.
11 no matching files were found.
50 the disk is (or was) full during extrac‐
tion.
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 meth‐
ods or unsupported decryption.
82 no files were found due to bad decryption
password(s). (If even one file is success‐
fully 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 con‐
junction 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 discus‐
sion in DECRYPTION above.
unzip's -M (``more'') option is overly simplistic in its
handling of screen output; as noted above, it fails to
detect the wrapping of long lines and may thereby cause
lines at the top of the screen to be scrolled off before
being read. unzip should detect and treat each occur‐
rence of line-wrap as one additional line printed. This
requires knowledge of the screen's width as well as its
height. In addition, unzip should detect the true screen
geometry on all systems.
Dates, times and permissions of stored directories are
not restored except under Unix.
[MS-DOS] When extracting or testing files from an archive
on a defective floppy diskette, if the ``Fail'' option is
chosen from DOS's ``Abort, Retry, Fail?'' message, older
versions of unzip may hang the system, requiring a
reboot. This problem appears to be fixed, but control-C
(or control-Break) can still be used to terminate unzip.
Under DEC Ultrix, unzip would sometimes fail on long zip‐
files (bad CRC, not always reproducible). This was
apparently due either to a hardware bug (cache memory) or
an operating system bug (improper handling of page
faults?). Since Ultrix has been abandoned in favor of
Digital Unix (OSF/1), this may not be an issue anymore.
[Unix] Unix special files such as FIFO buffers (named
pipes), block devices and character devices are not
restored even if they are somehow represented in the zip‐
file, 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 over‐
write 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 com‐
mon 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 ALSOfunzip(1L), zip(1L), zipcloak(1L), zipgrep(1L), zip‐
info(1L), zipnote(1L), zipsplit(1L)URL
The Info-ZIP home page is currently at ftp://ftp.info-
zip.org/pub/infozip/ .
AUTHORS
The primary Info-ZIP authors (current semi-active members
of the Zip-Bugs workgroup) are: Greg ``Cave Newt''
Roelofs (UnZip); Onno van der Linden (Zip); Jean-loup
Gailly (compression); Mark Adler (decompression, fUnZip);
Christian Spieler (UnZip maintance coordination, VMS, MS-
DOS, Windows 95, NT, shared code, general Zip and UnZip
integration and optimization); Mike White (Windows GUI,
Windows DLLs); Kai Uwe Rommel (OS/2); Paul Kienitz
(Amiga, Windows 95); 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 (Windows
95, NT); Steve Miller (Windows CE GUI), Johnny Lee (MS-
DOS, Windows 95, NT); and Dave Smith (Tandem NSK). 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)
Info-ZIP 16 April 2000 (v5.41) UNZIP(1L)
