Table of Contents
unzip - list, test and extract compressed files in a ZIP archive
unzip [-Z] [-cflptuvz[abjnoqsCLMVX$]] file[.zip] [file(s) ...] [-x xfile(s) ...]
[-d exdir]
unzip will list, test, or extract files from a ZIP
archive, commonly found on MS-DOS systems. The default behavior (with no
options) is to extract into the current directory (and subdirectories below
it) all files from the specified ZIP archive. A companion program, zip(1L)
,
creates ZIP archives; both programs are compatible with archives created
by PKWARE's PKZIP and PKUNZIP for MS-DOS, but in many cases the program options
or default behaviors differ.
- 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 interpreted or
- modified by the operating system,
particularly under Unix and VMS.) If no matches are found, the specification
is assumed to be a literal 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 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 command 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 of the user's home directory,
but ``-d~'' is treated as a literal subdirectory ``~'' of the current directory.
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 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 comments (if any)
are displayed. If a file was archived from a single-case file system (for
example, the old MS-DOS FAT file system) and the -L option was given, the
filename is converted to lowercase and is prefixed with a caret (^).
- -p
- extract
files to pipe (stdout). Nothing but the file data is sent to stdout, and
the files are always extracted in binary format, just as they are stored
(no conversions).
- -t
- test archive files. This option extracts each specified
file in memory and compares the CRC (cyclic redundancy check, an enhanced
checksum) of the expanded file with the original file's stored CRC value.
- -T
- [most OSes] set the timestamp on the archive(s) to that of the newest
file in each one. This corresponds to zip's -go option except that it can
be used on wildcard zipfiles (e.g., ``unzip -T \*.zip'') and is much faster.
- -u
- update
existing files and create new ones if needed. This option 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 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 compilation options that might affect the program's operation
(see also DECRYPTION below); and any options stored in environment variables
that might do the same (see ENVIRONMENT OPTIONS below). As a modifier it
works in conjunction with other options (e.g., -t) to produce more verbose
or debugging output; this is not yet fully implemented but will be in future
releases.
- -z
- display only the archive comment.
- -a
- convert text files.
Ordinarily all files are extracted exactly as they are stored (as ``binary''
files). The -a option causes files identified by zip as text files (those
with the `t' label in zipinfo listings, rather than `b') to be automatically
extracted as such, converting line endings, end-of-file characters and the
character set itself as 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
- [non-VMS]
treat all files as binary (no text conversions). This is a shortcut for
---a.
- -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
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 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-sensitive
one such as under Unix. By default unzip lists and extracts such filenames
exactly as they're stored (excepting truncation, conversion of unsupported
characters, etc.); this option causes the names of all files from certain
systems to be converted to lowercase.
- -M
- pipe all output through an internal
pager similar to the Unixmore(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, overwrite
all files, skip extraction of the current file, skip extraction of all
existing files, or rename the current file.
- -N
- [Amiga] extract file comments
as Amiga filenotes. File comments are created with the -c option of zip(1L)
,
or with the -N option of the Amiga port of zip(1L)
, which stores filenotes
as comments.
- -o
- overwrite existing files without prompting. This is a dangerous
option, so use it with care. (It is often used with -f, however, and is
the only way to overwrite directory EAs under OS/2.)
- -P password
- use password
to decrypt encrypted zipfile entries (if any). THIS IS INSECURE! Many
multi-user operating systems provide ways for any user to see the current
command line of any other user; even on stand-alone systems there is always
the threat of over-the-shoulder peeking. Storing the plaintext password as
part of a command line in an automated script is even worse. Whenever possible,
use the non-echoing, interactive prompt to enter passwords. (And where security
is truly important, use strong encryption such as Pretty Good Privacy instead
of the relatively weak encryption provided by standard zipfile utilities.)
- -q
- perform operations quietly (-qq = even quieter). 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 awkwardness 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 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 network-enabled versions of OS/2 (Warp Server with IBM LAN
Server/Requester 3.0 to 5.0; Warp Connect with IBM Peer 1.0), or security
ACLs under Windows NT. In most cases this will require special system privileges,
and doubling the option (-XX) under NT instructs unzip to use privileges
for extraction; but under Unix, for example, a user who belongs to several
groups can restore files owned by any of those groups, as long as the user
IDs match his or her own. Note that ordinary file attributes are always
restored--this option applies only to optional, extra ownership info available
on some operating systems. [NT's access control lists do not appear to be
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.
unzip's default
behavior may be modified via options placed in an environment variable.
This can be done with any option, but it is probably most useful with
the -a, -L, -C, -q, -o, or -n modifiers: make unzip auto-convert text files by
default, make it convert filenames from uppercase systems to lowercase,
make it match names case-insensitively, make it quieter, or make it always
overwrite or never overwrite files as it extracts them. For example, to
make unzip act as quietly as possible, only reporting errors, one would
use one of the following commands:
UNZIP=-qq; export UNZIPtUnix Bourne shell
setenv UNZIP -qqtUnix C shell
set UNZIP=-qqtOS/2 or MS-DOS
define UNZIP_OPTS
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 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 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.
Encrypted archives are fully
supported by Info-ZIP software, but due to United States export restrictions,
the encryption and decryption sources are not packaged with the regular
unzip and zip distributions. Since the crypt sources were written by Europeans,
however, they are freely available at sites throughout the world; see the
file ``WHERE'' in any Info-ZIP source or binary distribution for locations both
inside and outside the US.
Because of the separate distribution, not all
compiled versions of unzip 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 during the extraction because the ``decrypted''
bytes do not constitute a valid compressed data stream.
If the first password
fails the header check on some file, unzip will prompt for another password,
and so on until all files are extracted. If a password is not known, entering
a null password (that is, just a carriage return or ``Enter'') is taken as
a signal to skip all further prompting. Only unencrypted files in the archive(s)
will thereafter be extracted. (In fact, that's not quite true; older versions
of zip(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; 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
character encodings other than Latin-1 are not supported.
To use
unzip to extract all members of the archive letters.zip into the current
directory and subdirectories below it, creating any subdirectories as necessary:
unzip letters
To extract all members of letters.zip into the current directory only:
unzip -j letters
To test letters.zip, printing only a summary message indicating whether
the 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
(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
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
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
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.zipt(extra minuses don't hurt)
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''.
The exit status (or error level) approximates the
exit codes defined by PKWARE and takes on the following values, except
under VMS:
- 0
- normal; no errors or warnings detected.
- 1
- one or more warning
errors were encountered, but processing completed successfully anyway.
This includes zipfiles where one or more files was skipped due to unsupported
compression method or encryption with an unknown password.
- 2
- a generic error
in the zipfile format was detected. Processing may have completed 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 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*normal_unzip_exit_status)
for all other errors, where the `?' is 2 (error) for unzip values 2, 9-11
and 80-82, and 4 (fatal error) for the remaining ones (3-8, 50, 51). In addition,
there is a compilation option to expand upon this behavior: defining RETURN_CODES
results in a human-readable explanation of what the error status means.
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 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 occurrence 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 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 renaming; there
should additionally be a choice for creating a new version of the file.
In fact, the ``overwrite'' choice does create a new version; the old version
is not overwritten or deleted.
funzip(1L)
, zip(1L)
, zipcloak(1L)
,
zipgrep(1L)
, zipinfo(1L)
, zipnote(1L)
, zipsplit(1L)
The Info-ZIP home
page is currently at http://www.cdrom.com/pub/infozip/
.
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.
- v1.2t15 Mar 89
- Samuel
H. Smith
- v2.0t 9 Sep 89
- Samuel H. Smith
- v2.xtfall 1989
- many Usenet contributors
- v3.0t 1 May 90
- Info-ZIP (DPK, consolidator)
- v3.1t15 Aug 90
- Info-ZIP (DPK, consolidator)
- v4.0t 1 Dec 90
- Info-ZIP (GRR, maintainer)
- v4.1t12 May 91
- Info-ZIP
- v4.2t20 Mar 92
- Info-ZIP
(Zip-Bugs subgroup, GRR)
- v5.0t21 Aug 92
- Info-ZIP (Zip-Bugs subgroup, GRR)
- v5.01t15
Jan 93
- Info-ZIP (Zip-Bugs subgroup, GRR)
- v5.1t 7 Feb 94
- Info-ZIP (Zip-Bugs subgroup,
GRR)
- v5.11t 2 Aug 94
- Info-ZIP (Zip-Bugs subgroup, GRR)
- v5.12t28 Aug 94
- Info-ZIP
(Zip-Bugs subgroup, GRR)
- v5.2t30 Apr 96
- Info-ZIP (Zip-Bugs subgroup, GRR)
- v5.3t22
Apr 97
- Info-ZIP (Zip-Bugs subgroup, GRR)
- v5.31t31 May 97
- Info-ZIP (Zip-Bugs subgroup,
GRR)
- v5.32t 3 Nov 97
- Info-ZIP (Zip-Bugs subgroup, GRR)
- v5.4t28 Nov 98
- Info-ZIP
(Zip-Bugs subgroup, SPC)
Table of Contents