zip -- package and compress (archive) files

SYNOPSIS

zip [-AcdDefFghjklLmoqrRSTuvXz@!$] [- #] [-b path] [-n suffixes] [-t mmddyyyy] [-tt mmddyyyy] [zipfile [file1 file2 ...]] [-xi filelist]

DESCRIPTION

zip is a compression and file packaging utility. It is analogous to a combination of the UNIX commands tar and compress and is compatible with PKZIP (Phil Katz's ZIP for MSDOS systems).

A companion program (unzip) unpacks zip archives. The zip and unzip programs can work with archives produced by PKZIP, and PKZIP and PKUNZIP can work with archives produced by zip. zip version 2.3 is compatible with PKZIP 2.04. Note that PKUNZIP 1.10 cannot extract files produced by PKZIP 2.04 or zip 2.3. You must use PKUNZIP 2.04g or unzip 5.0p1 (or later versions) to extract them.

For brief help on zip and unzip, run each without specifying any parameters on the command line.

The zip utility is useful for packaging a set of files for distribution; for archiving files; and for saving disk space by temporarily compressing unused files or directories.

zip puts one or more compressed files into a single zip archive, along with information about the files (name, path, date, time of last modification, protection, and check information to verify file integrity). An entire directory structure can be packed into a zip archive with a single command. Compression ratios of 2:1 to 3:1 are common for text files. zip has one compression method (deflation) and can also store files without compression. zip automatically chooses the better of the two for each file to be compressed.

When given the name of an existing zip archive, zip replaces identically named entries in the zip archive or adds entries for new names. For example, if foo.zip exists and contains foo/file1 and foo/file2, and the directory foo contains the files foo/file1 and foo/file3, then

zip -r foo foo

replaces foo/file1 in foo.zip and adds foo/file3 to foo.zip. After this, foo.zip contains foo/file1, foo/file2, and foo/file3, with foo/file2 unchanged from before.

If the file list is specified as -@, zip takes the list of input files from standard input. This option can be used to powerful effect in conjunction with the find command. For example, to archive all the C source files in the current directory and its subdirectories:

find . -name "*.[ch]" -print | zip source -@

(note that the pattern must be quoted to keep the shell from expanding it). zip also accepts a single dash ("-") as zipfile, in which case it writes the zip file to standard output, allowing the output to be piped to another program. For example,

zip -r - . | dd of=/dev/nrst0 obs=16k

would write the zip output directly to a tape with the specified block size for the purpose of backing up the current directory.

zip also accepts a single dash ("-") as the name of a file to be compressed, in which case it reads the file from standard input, allowing zip to take input from another program. For example,

tar cf - . | zip backup -

would compress the output of the tar command for the purpose of backing up the current directory. This generally produces better compression than the previous example using the -r option, because zip can take advantage of redundancy between files. The backup can be restored using the command

unzip -p backup | tar xf -

When no zip file name is given and stdout is not a terminal, zip acts as a filter, compressing standard input to standard output. For example,

tar cf - . | zip | dd of=/dev/nrst0 obs=16k

is equivalent to

tar cf - . | zip - - | dd of=/dev/nrst0 obs=16k

zip archives created in this manner can be extracted with gunzip. For example,

dd if=/dev/nrst0 ibs=16k | gunzip | tar xvf -

When changing an existing zip archive, zip writes a temporary file with the new contents, and only replace the old one when the process of creating the new version has been completed without error.

If the name of the zip archive does not contain an extension, the extension .zip is added. If the name already contains an extension other than .zip, the existing extension is kept unchanged.

Options

-A

adjusts self-extracting executable archive. A self-extracting executable archive is created by prepending the SFX stub to an existing archive. The -A tells zip to adjust the entry offsets stored in the archive to take into account this "preamble" data.

-b path

uses the specified path for the temporary zip archive. For example,

zip -b /tmp stuff *

puts the temporary zip archive in the directory /tmp, copying over stuff.zip to the current directory when done. This option is only useful when updating an existing archive, and the file system containing this old archive does not have enough space to hold both old and new archive at the same time.

-c

adds one-line comments for each file. File operations (adding, updating) are done first, and the user is then prompted for a one-line comment for each file. Enter the comment followed by return, or just return for no comment.

-d

removes (deletes) entries from a zip archive. For example,

zip -d foo foo/tom/junk foo/harry/\* \*.o

removes the entry foo/tom/junk, all of the files that start with foo/harry/, and all of the files that end with .o (in any path). Note that shell path name expansion has been inhibited with backslashes, so that zip can see the asterisks, enabling zip to match on the contents of the zip archive instead of the contents of the current directory.

On Windows systems, -d is case sensitive when it matches names in the zip archive. This requires that file names be entered in uppercase if they were zipped by PKZIP on a Windows system.

-D

does not create entries in the zip archive for directories. Directory entries are created by default so that their attributes can be saved in the zip archive. The environment variable ZIPOPT can be used to change the default options. For example, sh,

ZIPOPT="-D"; export ZIPOPT

(The variable ZIPOPT can be used for any option except -i and -x and can include several options.) The option -D is a shorthand for -x "*/" but the latter cannot be set as default in the ZIPOPT environment variable.

-e

encrypts files as they are compressed. zip prompts for a key (and then again for confirmation) to use when encrypting files.

-f

replaces (freshens) an existing entry in the zip archive only if it has been modified more recently than the version already in the zip archive; unlike the update option (-u) this does not add files that are not already in the zip archive. For example,

zip -f foo

This command should be run from the same directory from which the original zip command was run, since paths stored in zip archives are always relative.

Note:

The timezone environment variable TZ should be set according to the local timezone in order for the -f, -u, and -o options to work correctly.

The reasons behind this are somewhat subtle but have to do with the differences between the UNIX- format file times (always in GMT) and most of the other operating systems (always local time) and the necessity to compare the two. A typical TZ value is MET-1METDST (Middle European time with automatic adjustment for "summertime" or Daylight Savings Time).

-F

fixes the zip archive. This option can be used if some portions of the archive are missing. It is not guaranteed to work, so you must make a backup of the original archive first.

When doubled as in -FF, the compressed sizes given inside the damaged archive are not trusted and zip scans for special signatures to identify the limits between the archive members. The single -F is more reliable if the archive is not too badly damaged, for example if it has only been truncated, so try this option first.

Neither option recovers archives that have been incorrectly transferred in ASCII mode instead of binary. After the repair, the -t option of unzip may show that some files have a bad CRC. Such files cannot be recovered; you can remove them from the archive using the -d option of zip.

-g

grows (appends to) the specified zip archive, instead of creating a new one. If this operation fails, zip attempts to restore the archive to its original state. If the restoration fails, the archive might become corrupted.

-h

displays the zip help information (this also appears if zip is run with no arguments).

-i filelist

includes only the specified files, as in

zip -r foo . -i \*.c

which includes only the files that end in .c in the current directory and its subdirectories. (Note for PKZIP users: the equivalent command is

pkzip -rP foo *.c

PKZIP does not allow recursion in directories other than the current one.) The backslash avoids the shell file name substitution, so that the name matching is performed by zip at all directory levels.

-j

stores just the name of a saved file (junks the path), and do not store directory names. By default, zip stores the full path (relative to the current path).

-J

strips any prepended data (for example, a SFX stub) from the archive.

-k

attempt to convert the names and paths to conform to MSDOS, stores only the MSDOS attribute (just the user write attribute from UNIX), and marks the entry as made under MSDOS (even though it was not); for compatibility with PKUNZIP under MSDOS which cannot handle certain names such as those with two dots.

-l

translates the UNIX end-of-line character LF into the MSDOS convention CR LF. This option should not be used on binary files. This option can be used on UNIX systems if the zip file is intended for PKUNZIP under MSDOS. If the input files already contain CR LF, this option adds an extra CR. This ensures that unzip -a on UNIX systems gets back an exact copy of the original file, to undo the effect of zip -l.

-ll

translates the MSDOS end-of-line character CR LF into UNIX LF. This option should not be used on binary files. This option can be used on MSDOS if the zip file is intended for unzip on UNIX systems.

-L

displays the zip license.

-m

moves the specified files into the zip archive; actually, this deletes the target directories/files after making the specified zip archive. If a directory becomes empty after removal of the files, the directory is also removed. No deletions are done until zip has created the archive without error. This is useful for conserving disk space, but is potentially dangerous so it is recommended to use it in combination with -T to test the archive before removing all input files.

-n suffixes

does not attempt to compress files named with the given suffixes. Such files are simply stored (0% compression) in the output zip file, so that zip does not waste its time trying to compress them. The suffixes are separated by either colons or semicolons. For example,

zip -rn .Z:.zip:.tiff:.gif:.snd foo foo

copies everything from foo into foo.zip, but stores any files that end in .Z, .zip, .tiff, .gif, or .snd without trying to compress them (image and sound files often have their own specialized compression methods). By default, zip does not compress files with extensions in the list .Z:.zip:.zoo:.arc:.lzh:.arj. Such files are stored directly in the output archive. The environment variable ZIPOPT can be used to change the default options. For example, with csh,

setenv ZIPOPT "-n .gif:.zip"

To attempt compression on all files, use

zip -n : foo

The maximum compression option -9 also attempts compression on all files regardless of extension.

-o

sets the "last modified" time of the zip archive to the latest (oldest) "last modified" time found among the entries in the zip archive. This can be used without any other operations, if desired. For example,

zip -o foo

changes the last modified time of foo.zip to the latest time of the entries in foo.zip.

-q

quiet mode; eliminates informational messages and comment prompts. (Useful, for example, in shell scripts and background tasks).

-r

travels the directory struct recursively; for example,

zip -r foo foo

In this case, all the files and directories in foo are saved in a zip archive named foo.zip, including files with names starting with ".", since the recursion does not use the shell's file name substitution mechanism. If you wish to include only a specific subset of the files in directory foo and its subdirectories, use the -i option to specify the pattern of files to be included. You should not use -r with the name ".*", since that matches ".." which attempts to zip up the parent directory (probably not what was intended).

-R

travels the directory struct recursively starting at the current directory; for example,

zip -R foo '*.c'

In this case, all the files matching *.c in the tree starting at the current directory are stored into a zip archive named foo.zip. Note for PKZIP users: the equivalent command is

pkzip -rP foo *.c

-S

includes system and hidden files. This option is effective on some systems only; it is ignored on UNIX systems.

-t mmddyyyy

does not operate on files modified prior to the specified date, where mm is the month (0-12), dd is the day of the month (1-31), and yyyy is the year. The ISO 8601 date format yyyy-mm-dd is also accepted. For example,

zip -rt 12071991 infamy foo
zip -rt 1991-12-07 infamy foo

adds all the files in foo and its subdirectories that were last modified on or after 7 December 1991, to the zip archive infamy.zip.

-tt mmddyyyy

does not operate on files modified on or after the specified date, where mm is the month (0-12), dd is the day of the month (1-31), and yyyy is the year. The ISO 8601 date format yyyy-mm-dd is also accepted. For example,

zip -rtt 12071991 infamy foo
zip -rtt 1991-12-07 infamy foo

adds all the files in foo and its subdirectories that were last modified before 7 December 1991, to the zip archive infamy.zip.

-T

tests the integrity of the new zip file. If the check fails, the old zip file is unchanged and (with the -m option) no input files are removed.

-u

replaces (updates) an existing entry in the zip archive only if it has been modified more recently than the version already in the zip archive. For example,

zip -u stuff *

adds any new files in the current directory, and update any files that have been modified since the zip archive stuff.zip was last created/modified (note that zip does not try to pack stuff.zip into itself when you do this).

Note:: The -u option with no arguments acts like the -f (freshen) option.

-v

enables verbose mode or prints diagnostic version information.

Normally, when applied to real operations, this option enables the display of a progress indicator during compression and requests verbose diagnostic information about zipfile structure oddities.

When -v is the only command line argument, and stdout is not redirected to a file, a diagnostic screen is printed. In addition to the help screen header with program name, version, and release date, some pointers to the Info-ZIP home and distribution sites are given. Then, it shows information about the target environment (compiler type and version, OS version, compilation date and the enabled optional features used to create the zip executable.

-x filelist

explicitly excludes the specified files, as in

zip -r foo foo -x \*.o

which includes the contents of foo in foo.zip while excluding all the files that end in .o. The backslash avoids the shell file name substitution, so that the name matching is performed by zip at all directory levels.

-X

does not save extra file attributes (Extended Attributes on OS/2, uid/gid and file times on UNIX systems).

-z

prompts for a multi-line comment for the entire zip archive. The comment is ended by a line containing just a period, or an end of file condition ( CTRL-D on UNIX system, CTRL-Z on MSDOS, OS/2, and VAX/VMS systems). The comment can be taken from a file, for example,

zip -z foo < foowhat

-#

regulates the speed of compression using the specified digit #, where -0 indicates no compression (store all files), -1 indicates the fastest compression method (less compression) and -9 indicates the slowest compression method (optimal compression, ignores the suffix list). The default compression level is -6.

-!

uses privileges (if granted) to obtain all aspects of Windows NT/2000/XP/2003/Vista/7/2008 security.

-@

takes the list of input files from standard input. File names containing spaces must be quoted using single quotes, as in 'file name'.

-$

includes the volume label for the the drive holding the first file to be compressed. If you want to include only the volume label or to force a specific drive, use the drive name as first file name, as in

zip -$ foo a: c:bar

This option is effective on some systems only (MSDOS and OS/2); it is ignored on UNIX systems.

Pattern Matching

This section applies only to UNIX systems. Watch this space for details on MSDOS and VMS operation.

The UNIX shells (sh and csh) do file name substitution on command arguments. The special characters are:

?     match any single character

*     match any number of characters (including none)

[]    match any character in the range indicated within
      the brackets (example: [a-f], [0-9]).

When these characters are encountered (without being escaped with a backslash or quotes), the shell looks for files relative to the current path that match the pattern, and replace the argument with a list of the names that matched.

The zip program can do the same matching on names that are in the zip archive being modified or, in the case of the -x (exclude) or -i (include) options, on the list of files to be operated on, by using backslashes or quotes to tell the shell not to do the name expansion. In general, when zip encounters a name in the list of files to do, it first looks for the name in the file system. If it finds it, it then adds it to the list of files to do. If it does not find it, it looks for the name in the zip archive being modified (if it exists), using the pattern matching characters described above, if present. For each match, it adds that name to the list of files to be processed, unless this name matches one given with the -x option, or does not match any name given with the -i option.

The pattern matching includes the path, and so patterns like \*.o match names that end in ".o", no matter what the path prefix is. Note that the backslash must precede every special character (that is, ?*[]), or the entire argument must be enclosed in double quotes ("").

In general, use backslash to make zip do the pattern matching with the -f (freshen) and -d (delete) options, and sometimes after the -x (exclude) option when used with an appropriate operation (add, -u, -f, or -d).

EXAMPLES

The simplest example:

zip stuff *

creates the archive stuff.zip (assuming it does not exist) and puts all the files in the current directory in it, in compressed form (the .zip suffix is added automatically, unless that archive name given contains a dot already; this allows the explicit specification of other suffixes).

Because of the way the shell does file name substitution, files starting with "." are not included; to include these as well, use

zip stuff .* *

Even this does not include any subdirectories from the current directory.

To zip up an entire directory, the command

zip -r foo foo

creates the archive foo.zip, containing all the files and directories in the directory foo that is contained within the current directory.

You may want to make a zip archive that contains the files in foo, without recording the directory name, foo. You can use the -j option to leave off the paths, as in

zip -j foo foo/*

If you are short on disk space, you might not have enough room to hold both the original directory and the corresponding compressed zip archive. In this case, you can create the archive in steps using the -m option. If foo contains the subdirectories tom, dick, and harry, you can use

zip -rm foo foo/tom
zip -rm foo foo/dick
zip -rm foo foo/harry

where the first command creates foo.zip, and the next two add to it. At the completion of each zip command, the last created archive is deleted, making room for the next zip command to function.

ENVIRONMENT VARIABLES

TK_ARCHIVE_CHARSET

Contains the format to be used by cpio, tar, pax, vpax, zip, or unzip when reading and writing file names to an archive. The value must be one of ASCII_ANSI, ASCII_OEM, or UTF-8 (or their equivalents) as described in the File Character Formats section of the unicode reference page.

When this variable is unset or it is set to a value other than those listed earlier, the default OEM character set is used.

ZIPOPTS

contains default options that are used when running zip.

ZIP

is the same as ZIPOPTS

DIAGNOSTICS

The exit status (or error level) approximates the exit codes defined by PKWARE and takes on the following values:

0: normal; no errors or warnings detected.
2: unexpected end of zip file.
3: a generic error in the zipfile format was detected. Processing may have completed successfully anyway; some broken zipfiles created by other archivers have simple workarounds.
4: zip was unable to allocate memory for one or more buffers during program initialization.
5: a severe error in the zipfile format was detected. Processing probably failed immediately.
7: invalid comment format.
8: zip -T failed or out of memory.
9: the user aborted zip prematurely with CTRL-C (or similar).
10: zip encountered an error while using a temp file.
11: read or seek error.
12: zip has nothing to do.
13: missing or empty zip file.
14: error writing to a file.
15: zip was unable to create a file to write to.
16: bad command line parameters.
18: zip could not open a specified file to read.

BUGS

zip 2.3 is not compatible with PKUNZIP 1.10. Use zip 1.1 to produce zip files that can be extracted by PKUNZIP 1.10.

zip files produced by zip 2.3 must not be updated by zip 1.1 or PKZIP 1.10, if they contain encrypted members or if they have been produced in a pipe or on a non-seekable device. The old versions of zip or PKZIP would create an archive with an incorrect format. The old versions can list the contents of the zip file but cannot extract it anyway (because of the new compression algorithm). If you do not use encryption and use regular disk files, you do not have to care about this problem.

AUTHORS

Copyright (C) 1990-1996 Mark Adler, Richard B. Wales, Jean-loup Gailly, Onno van der Linden, Kai Uwe Rommel, Igor Mandrichenko, John Bush and Paul Kienitz. Permission is granted to any individual or institution to use, copy, or redistribute this software so long as all of the original files are included, that it is not sold for profit, and that this copyright notice is retained.

ACKNOWLEDGEMENTS

Thanks to R. P. Byrne for his Shrink.Pas program, which inspired this project, and from which the shrink algorithm was stolen; to Phil Katz for placing in the public domain the zip file format, compression format, and .ZIP file name extension, and for accepting minor changes to the file format; to Steve Burg for clarifications on the deflate format; to Haruhiko Okumura and Leonid Broukhis for providing some useful ideas for the compression algorithm; to Keith Petersen, Rich Wales, Hunter Goatley and Mark Adler for providing a mailing list and ftp site for the INFO-ZIP group to use; and most importantly, to the INFO-ZIP group itself (listed in the file infozip.who) without whose tireless testing and bug-fixing efforts a portable zip would not have been possible. Finally we should thank (blame) the first INFO-ZIP moderator, David Kirschbaum, for getting us into this mess in the first place. The manual page was rewritten for UNIX by R. P. C. Rodgers.

PORTABILITY

Windows 2000. Windows XP. Windows Server 2003. Windows Vista. Windows 7. Windows Server 2008. All UNIX systems.

zip is also available for other platforms including MSDOS, OS/2, Minix, Atari, Macintosh, Amiga, and Acorn RISC OS. Versions of zip on these platforms may feature a slightly different set of options.

The MKS Toolkit version of zip does not support the -P option found on some other platforms.

AVAILABILITY

MKS Toolkit for Power Users
MKS Toolkit for System Administrators
MKS Toolkit for Developers
MKS Toolkit for Interoperability
MKS Toolkit for Professional Developers
MKS Toolkit for Enterprise Developers
MKS Toolkit for Enterprise Developers 64-Bit Edition

zip
package and compress (archive) files

Command