UNZIP

Section: Misc. Reference Manual Pages (1L)
Updated: 7 Feb 94 (v5.1)
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NAME

unzip - list, test and extract compressed files in a ZIP archive

SYNOPSIS

unzip [-Z] [-cflptuvz[ajnoqsUV$]] 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 PKWARE's PKZIP and PKUNZIP for MS-DOS.

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 which 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; just specify the .exe suffix (if any) explicitly.

[file(s)]

An optional list of archive members to be processed. 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 which 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 immediately after the zipfile specification, or between the file(s) and the -x option.

OPTIONS

-Z: zipinfo(1) mode. If the first option on the command line is -Z, the remaining options are taken to be zipinfo(1) options. See the appropriate manual page for a description of these options.
-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.
-f: freshen existing files, i.e., extract only those files which already exist on disk and which are newer than the disk copies. By default unzip queries before overwriting, but the -o option may be used to suppress the queries.
-l: list archive files (short format). The name, uncompressed file size and modification date and time of each specified file is printed, along with totals for all files specified. If a file was archived from a single-case file system (for example, the MS-DOS FAT file system) and the -U option was not given, the filename is converted to lowercase and is prefixed with a caret (^). In addition, the archive comment and individual file comments (if any) are displayed.
-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.
-u: update existing files and create new ones if needed. This option performs the same function as the -f option, extracting (with query) files which are newer than those with the same name on disk, and in addition it extracts those files which do not already exist on disk.
-v: list archive files (verbose format). In addition to the information given by the -l option, the compression method, compressed size, compression ratio and 32-bit CRC is listed.
-z: display only the archive comment.

MODIFIERS

-a: convert text files. Ordinarily all files are extracted exactly as they are stored (as ``binary'' files). The -a option causes files identified by zip as text files (those with the `t' label in zipinfo listings, rather than `b') to be automatically extracted as such, converting line endings, end-of-file characters and the character set itself as 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.
-j: junk paths. The archive's directory structure is not recreated; all files are deposited in the extraction directory (by default, the current one).
-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 which 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.
-o: overwrite existing files without prompting. This is a dangerous option, so use it with care. (It is often used with -f, however.)
-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 which 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: leave filenames uppercase if created under MS-DOS, VMS, etc. Depending on the archiver, files archived under single-case filesystems may be stored as all-uppercase names; this can be awkward when extracting to a case-preserving filesystem such as OS/2 HPFS or a case-sensitive one such as under Unix. By default unzip converts such filenames to lowercase; this option causes all filenames to be extracted exactly as they're stored (excepting truncation, conversion of unsupported characters, etc.).
-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 filesystems which limit filenames to particularly short lengths, the version numbers may be truncated or stripped regardless of this option.)
-X: [VMS] restore owner/protection info (may require system privileges). Ordinary file attributes are always restored, but this option allows UICs to be restored as well. [The next version of unzip will support Unix UID/GID info as well, and possibly NT permissions.]
-$: [MS-DOS, OS/2, NT, Amiga] 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.

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 -q, -a, -o, or -n modifiers: make unzip quieter by default, make it auto-convert text files, 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 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 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).

EXAMPLES

To use unzip to extract all members of the archive letters.zip into the current directory and subdirectories below it, creating any subdirectories as necessary:

unzip letters

To extract all members of letters.zip into the current directory only:

unzip -j letters

To test letters.zip, printing only a summary message indicating whether the archive is OK or not:

unzip -tq letters

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

(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 example below.) 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 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 to date 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

In the last five examples, assume that UNZIP or UNZIP_OPTS is set to -q. To do a singly quiet listing:

unzip -l file

To do a doubly quiet listing:

unzip -ql file

To do a standard listing:

unzip --ql file

unzip -l-q file

unzip -l--q file (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 which is worth making a habit of doing. With luck unzip will report ``No errors detected in zipfile.zip,'' after which one may breathe a sigh of relief.

BUGS

[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, unzip may hang the system, requiring a reboot. Instead, press control-C (or control-Break) to terminate unzip.

Under DEC Ultrix, unzip will sometimes fail on long zipfiles (bad CRC, not always reproducible). This is apparently due either to a hardware bug (cache memory) or an operating system bug (improper handling of page faults?).

Dates and times of stored directories are not restored.

[OS/2] Extended attributes for existing directories are never updated. This is a limitation of the operating system; unzip has no way to determine whether the stored attributes are newer or older than the existing ones.

[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.

AUTHORS

The primary Info-ZIP authors (current zip-bugs workgroup) are: Jean-loup Gailly (Zip), Greg R. Roelofs (UnZip), Mark Adler (decompression, fUnZip), Kai Uwe Rommel (OS/2), Igor Mandrichenko (VMS), John Bush and Paul Kienitz (Amiga), Antoine Verheijen (Macintosh), Chris Herborth (Atari), Henry Gessau (NT), and Robert Heath (Windows). The author of the original unzip code upon which Info-ZIP's is based was Samuel H. Smith; Carl Mascott did the first Unix port; and David P. Kirschbaum organized and led Info-ZIP in its early days. The full list of contributors to UnZip has grown quite large; please refer to the CONTRIBS file in the UnZip source distribution for a more complete list.

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, maint.)
v5.0 21 Aug 92: Info-ZIP (zip-bugs subgroup; GRR, maint.)
v5.1 7 Feb 94: Info-ZIP (zip-bugs subgroup; GRR, maint.)

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