UNZIPSFX(1L) UNZIPSFX(1L)
NAME
unzipsfx - self-extracting stub for prepending to ZIP archives
SYNOPSIS
<name of unzipsfx+archive combo> [-cfptuz[ajnoqsCLV$]] [file(s) ... [-x xfile(s) ...]]
DESCRIPTION
unzipsfx is a modified version of unzip(1L) 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. Because the executable stub adds bulk to the archive (the whole purpose of which is to be
as small as possible), a number 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 decom‐
press older compression formats (the ``reduce,'' ``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 default.
Note that self-extracting archives made with unzipsfx are no more (or less) portable across different operat‐
ing systems 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 embedded archive as with any normal zipfile, although it will generate a harmless warning
about extra bytes at the beginning 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 zipfile.
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 sys‐
tem, particularly 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 subdirectories. 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]
in the zipfile comment.
See unzip(1L) for a more complete description of these options.
MODIFIERS
unzipsfx currently supports all unzip(1L) modifiers: -a (convert text files), -n (never overwrite), -o (over‐
write without prompting), -q (operate quietly), -C (match names case-insensitively), -L (convert uppercase-OS
names to lowercase), -j (junk paths) and -V (retain version numbers); plus the following operating-system spe‐
cific 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 conver‐
sion will of course continue to be supported since the zipfile format implies ASCII storage of text files.)
See unzip(1L) for a more complete description of these modifiers.
ENVIRONMENT OPTIONS
unzipsfx uses the same environment variables as unzip(1L) does, although this is likely to be an issue only
for the person creating and testing the self-extracting archive. See unzip(1L) for details.
DECRYPTION
Decryption is supported exactly as in unzip(1L); that is, interactively with a non-echoing prompt for the
password(s). See unzip(1L) 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 oper‐
ating 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
permissions 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 com‐
mand):
copy /b unzipsfx.exe+letters.zip letters.exe
zip -A letters.exe
(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 neces‐
sary:
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 oper‐
ating systems, and therefore neither are the resulting archives. For some architectures there is limited
portability, however (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
technically 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 directory 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 situation is not known for AmigaDOS, Atari TOS, MacOS, etc.
As noted above, a number of the normal unzip(1L) 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.
DIAGNOSTICS
unzipsfx's exit status (error level) is identical to that of unzip(1L); see the corresponding man page.
SEE ALSO
funzip(1L), unzip(1L), zip(1L), zipcloak(1L), zipgrep(1L), zipinfo(1L), zipnote(1L), zipsplit(1L)
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(1L)
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(1L)
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