Manual: unzipsfx
UNZIPSFX(1) General Commands Manual UNZIPSFX(1)
NAME
unzipsfx - self-extracting stub for prepending to ZIP archives
SYNOPSIS
[-cfptuz[ajnoqsCLV$]] [file(s) ... [-x xfile(s) ...]]
DESCRIPTION
unzipsfx is a modified version of unzip(1) designed to be prepended to existing ZIP archives in order to form self-
extracting archives. Instead of taking its first non-flag argument to be the zipfile(s) to be extracted, unzipsfx
seeks itself under the name by which it was invoked and tests or extracts the contents of the appended archive. Be‐
cause the executable stub adds bulk to the archive (the whole purpose of which is to be as small as possible), a num‐
ber of the less-vital capabilities in regular unzip have been removed. Among these are the usage (or help) screen,
the listing and diagnostic functions (-l and -v), the ability to decompress older compression formats (the ``re‐
duce,'' ``shrink'' and ``implode'' methods). The ability to extract to a directory other than the current one can be
selected as a compile-time option, which is now enabled by default since UnZipSFX version 5.5. Similarly, decryption
is supported as a compile-time option but should be avoided unless the attached archive contains encrypted files.
Starting with release 5.5, another compile-time option adds a simple ``run command after extraction'' feature. This
feature is currently incompatible with the ``extract to different directory'' feature and remains disabled by de‐
fault.
Note that self-extracting archives made with unzipsfx are no more (or less) portable across different operating sys‐
tems than is the unzip executable itself. In general a self-extracting archive made on a particular Unix system, for
example, will only self-extract under the same flavor of Unix. Regular unzip may still be used to extract the embed‐
ded archive as with any normal zipfile, although it will generate a harmless warning about extra bytes at the begin‐
ning of the zipfile. Despite this, however, the self-extracting archive is technically not a valid ZIP archive, and
PKUNZIP may be unable to test or extract it. This limitation is due to the simplistic manner in which the archive is
created; the internal directory structure is not updated to reflect the extra bytes prepended to the original zip‐
file.
ARGUMENTS
[file(s)]
An optional list of archive members to be processed. Regular expressions (wildcards) similar to those in Unix
egrep(1) may be used to match multiple members. These wildcards 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, par‐
ticularly under Unix and VMS.)
[-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,
``foosfx *.[ch] -x */*'' would extract all C source files in the main directory, but none in any subdirecto‐
ries. Without the -x option, all C source files in all directories within the zipfile would be extracted.
If unzipsfx is compiled with SFX_EXDIR defined, the following option is also enabled:
[-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 per‐
mission to write to the directory). The option and directory may be concatenated without any white space be‐
tween 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.
OPTIONS
unzipsfx supports the following unzip(1) options: -c and -p (extract to standard output/screen), -f and -u (freshen
and update existing files upon extraction), -t (test archive) and -z (print archive comment). All normal listing op‐
tions (-l, -v and -Z) have been removed, but the testing option (-t) may be used as a ``poor man's'' listing. Alter‐
natively, those creating self-extracting archives may wish to include a short listing in the zipfile comment.
See unzip(1) for a more complete description of these options.
MODIFIERS
unzipsfx currently supports all unzip(1) modifiers: -a (convert text files), -n (never overwrite), -o (overwrite
without prompting), -q (operate quietly), -C (match names case-insensitively), -L (convert uppercase-OS names to low‐
ercase), -j (junk paths) and -V (retain version numbers); plus the following operating-system specific options: -X
(restore VMS owner/protection info), -s (convert spaces in filenames to underscores [DOS, OS/2, NT]) and -$ (restore
volume label [DOS, OS/2, NT, Amiga]).
(Support for regular ASCII text-conversion may be removed in future versions, since it is simple enough for the
archive's creator to ensure that text files have the appropriate format for the local OS. EBCDIC conversion will of
course continue to be supported since the zipfile format implies ASCII storage of text files.)
See unzip(1) for a more complete description of these modifiers.
ENVIRONMENT OPTIONS
unzipsfx uses the same environment variables as unzip(1) does, although this is likely to be an issue only for the
person creating and testing the self-extracting archive. See unzip(1) for details.
DECRYPTION
Decryption is supported exactly as in unzip(1); that is, interactively with a non-echoing prompt for the password(s).
See unzip(1) for details. Once again, note that if the archive has no encrypted files there is no reason to use a
version of unzipsfx with decryption support; that only adds to the size of the archive.
AUTORUN COMMAND
When unzipsfx was compiled with CHEAP_SFX_AUTORUN defined, a simple ``command autorun'' feature is supported. You may
enter a command into the Zip archive comment, using the following format:
$AUTORUN$>[command line string]
When unzipsfx recognizes the ``$AUTORUN$>'' token at the beginning of the Zip archive comment, the remainder of the
first line of the comment (until the first newline character) is passed as a shell command to the operating system
using the C rtl ``system'' function. Before executing the command, unzipsfx displays the command on the console and
prompts the user for confirmation. When the user has switched off prompting by specifying the -q option, autorun
commands are never executed.
In case the archive comment contains additional lines of text, the remainder of the archive comment following the
first line is displayed normally, unless quiet operation was requested by supplying a -q option.
EXAMPLES
To create a self-extracting archive letters from a regular zipfile letters.zip and change the new archive's permis‐
sions to be world-executable under Unix:
cat unzipsfx letters.zip > letters
chmod 755 letters
zip -A letters
To create the same archive under MS-DOS, OS/2 or NT (note the use of the /b [binary] option to the copy command):
copy /b unzipsfx.exe+letters.zip letters.exe
zip -A letters.exe
Under VMS:
copy unzipsfx.exe,letters.zip letters.exe
letters == "$currentdisk:[currentdir]letters.exe"
zip -A letters.exe
(The VMS append command may also be used. The second command installs the new program as a ``foreign command'' capa‐
ble of taking arguments. The third line assumes that Zip is already installed as a foreign command.) Under Amiga‐
DOS:
MakeSFX letters letters.zip UnZipSFX
(MakeSFX is included with the UnZip source distribution and with Amiga binary distributions. ``zip -A'' doesn't work
on Amiga self-extracting archives.) To test (or list) the newly created self-extracting archive:
letters -t
To test letters quietly, printing only a summary message indicating whether the archive is OK or not:
letters -tqq
To extract the complete contents into the current directory, recreating all files and subdirectories as necessary:
letters
To extract all *.txt files (in Unix quote the `*'):
letters *.txt
To extract everything except the *.txt files:
letters -x *.txt
To extract only the README file to standard output (the screen):
letters -c README
To print only the zipfile comment:
letters -z
LIMITATIONS
The principle and fundamental limitation of unzipsfx is that it is not portable across architectures or operating
systems, and therefore neither are the resulting archives. For some architectures there is limited portability, how‐
ever (e.g., between some flavors of Intel-based Unix).
Another problem with the current implementation is that any archive with ``junk'' prepended to the beginning techni‐
cally is no longer a zipfile (unless zip(1) is used to adjust the zipfile offsets appropriately, as noted above).
unzip(1) takes note of the prepended bytes and ignores them since some file-transfer protocols, notably MacBinary,
are also known to prepend junk. But PKWARE's archiver suite may not be able to deal with the modified archive unless
its offsets have been adjusted.
unzipsfx has no knowledge of the user's PATH, so in general an archive must either be in the current directory when
it is invoked, or else a full or relative path must be given. If a user attempts to extract the archive from a di‐
rectory in the PATH other than the current one, unzipsfx will print a warning to the effect, ``can't find myself.''
This is always true under Unix and may be true in some cases under MS-DOS, depending on the compiler used (Microsoft
C fully qualifies the program name, but other compilers may not). Under OS/2 and NT there are operating-system calls
available that provide the full path name, so the archive may be invoked from anywhere in the user's path. The situ‐
ation is not known for AmigaDOS, Atari TOS, MacOS, etc.
As noted above, a number of the normal unzip(1) functions have been removed in order to make unzipsfx smaller: usage
and diagnostic info, listing functions and extraction to other directories. Also, only stored and deflated files are
supported. The latter limitation is mainly relevant to those who create SFX archives, however.
VMS users must know how to set up self-extracting archives as foreign commands in order to use any of unzipsfx's op‐
tions. This is not necessary for simple extraction, but the command to do so then becomes, e.g., ``run letters'' (to
continue the examples given above).
unzipsfx on the Amiga requires the use of a special program, MakeSFX, in order to create working self-extracting
archives; simple concatenation does not work. (For technically oriented users, the attached archive is defined as a
``debug hunk.'') There may be compatibility problems between the ROM levels of older Amigas and newer ones.
All current bugs in unzip(1) exist in unzipsfx as well.
DIAGNOSTICS
unzipsfx's exit status (error level) is identical to that of unzip(1); see the corresponding man page.
SEE ALSO
funzip(1), unzip(1), zip(1), zipcloak(1), zipgrep(1), zipinfo(1), zipnote(1), zipsplit(1)
URL
The Info-ZIP home page is currently at
http://www.info-zip.org/pub/infozip/
or
ftp://ftp.info-zip.org/pub/infozip/ .
AUTHORS
Greg Roelofs was responsible for the basic modifications to UnZip necessary to create UnZipSFX. See unzip(1) for the
current list of Zip-Bugs authors, or the file CONTRIBS in the UnZip source distribution for the full list of Info-ZIP
contributors.
Info-ZIP 20 April 2009 (v6.0) UNZIPSFX(1)