unzipsfx.1

压缩算法的源代码

.\" Info-ZIP grants permission to any individual or institution to use, copy,
.\" or redistribute this software, so long as:  (1) all of the original files
.\" are included; (2) it is not sold for profit; and (3) this notice is re-
.\" tained.
.\"
.\" unzipsfx.1 by Greg Roelofs
.\"
.\" =========================================================================
.\" define .Y macro (for user-command examples; normal Courier font):
.de Y
.ft CW
.in +4n
.nf
\&\\$1
.ft
.in
.fi
..
.\" =========================================================================
.TH UNZIPSFX 1L "28 Aug 94 (v5.12)"
.SH NAME
unzipsfx \- self-extracting stub for prepending to ZIP archives
.PD
.\" =========================================================================
.SH SYNOPSIS
\fB<name of unzipsfx+archive combo>\fP [\fB\-cfptuz\fP[\fBajnoqsCLV$\fP]]
[\fIfile(s)\fP\ .\|.\|. [\fB\-x\fP\ \fIxfile(s)\fP\ .\|.\|.]]
.PD
.\" =========================================================================
.SH DESCRIPTION
\fIunzipsfx\fP is a modified version of \fIunzip\fP(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, 
\fIunzipsfx\fP 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 regular version's less-vital 
capabilities have been removed.  Among these are the usage (or help) screen,
the listing and diagnostic functions (\fB\-l\fP and \fB\-v\fP), the ability 
to decompress older compression formats (the ``reduce,'' ``shrink'' and 
``implode'' methods), and the ability to extract to a directory other than 
the current one.  Decryption is supported as a compile-time option but 
should be avoided unless the attached archive contains encrypted files.
.LP
\fBNote that
self-extracting archives made with\fP \fIunzipsfx\fP \fBare no more (or less)
portable across different operating systems than is 
the\fP \fIunzip\fP \fBexecutable itself.\fP  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 \fIunzip\fP 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.
.PD
.\" =========================================================================
.SH ARGUMENTS
.IP [\fIfile(s)\fP]
An optional list of archive members to be processed.
Regular expressions (wildcards) similar to those in Unix \fIegrep\fP(1)
may be used to match multiple members.  These wildcards may contain:
.RS
.IP *
matches a sequence of 0 or more characters
.IP ?
matches exactly 1 character
.IP [.\|.\|.]
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 \fIexcept\fP
the characters inside the brackets is considered a match).
.RE
.IP
(Be sure to quote any character which might otherwise be interpreted or
modified by the operating system, particularly under Unix and VMS.)
.IP [\fB\-x\fP\ \fIxfile(s)\fP]
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, ``\fCfoosfx *.[ch] -x */*\fR'' would extract all C source files
in the main directory, but none in any subdirectories.  Without the \fB\-x\fP
option, all C source files in all directories within the zipfile would be
extracted.
Unlike in \fIunzip\fP(1L), the \fB\-x\fP option may only be used if one or
more \fIfiles\fP are given.  This is because there is no zipfile separating
the normal options from the \fB\-x\fP option, so \fIunzipsfx\fP sees it as
another normal option.  For historical reasons, the ``normal'' \fB\-x\fP is 
silently ignored.  See the \fBEXAMPLES\fP section below.
.LP
If \fIunzipsfx\fP is compiled with SFX_EXDIR defined, the following option
is also enabled:
.IP [\fB\-d\fP\ \fIexdir\fP]
An optional directory to which to extract files.  By default, all files
and subdirectories are recreated in the current directory; the \fB\-d\fP
option allows extraction in an arbitrary directory (always assuming one
has permission to write to the directory).  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,
``\fC\-d\ ~\fR'' (tilde) is expanded by Unix C shells into the name 
of the user's home directory, but ``\fC\-d~\fR'' is treated as a
literal subdirectory ``\fB~\fP'' of the current directory.  As with 
\fB\-x\fP, the \fB\-d\fP option may only be used if one or more \fIfiles\fP
are given.
.PD
.\" =========================================================================
.SH OPTIONS
\fIunzipsfx\fP supports the following \fIunzip\fP(1L) options:  \fB\-c\fP
and \fB\-p\fP (extract to standard output/screen), \fB\-f\fP and \fB\-u\fP
(freshen and update existing files upon extraction), \fB\-t\fP (test
archive) and \fB\-z\fP (print archive comment).  All normal listing options
(\fB\-l\fP, \fB\-v\fP and \fB\-Z\fP) have been removed, but the testing
option (\fB\-t\fP) may be used as a ``poor man's'' listing.  Alternatively,
those creating self-extracting archives may wish to include a short listing 
in the zipfile comment.
.LP
See \fIunzip\fP(1L) for a more complete description of these options.
.PD
.\" =========================================================================
.SH MODIFIERS
\fIunzipsfx\fP currently supports all \fIunzip\fP(1L) modifiers:  \fB\-a\fP 
(convert text files), \fB\-n\fP (never overwrite), \fB\-o\fP (overwrite 
without prompting), \fB\-q\fP (operate quietly), \fB\-C\fP (match names 
case-insenstively), \fB\-L\fP (convert uppercase-OS names to lowercase),
\fB\-j\fP (junk paths) and \fB\-V\fP (retain version numbers); plus the
following operating-system specific options:  \fB\-X\fP (restore VMS 
owner/protection info), \fB\-s\fP (convert spaces in filenames to underscores
[DOS, OS/2, NT]) and \fB\-$\fP (restore volume label [DOS, OS/2, NT, Amiga]).
.LP
(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.)
.LP
See \fIunzip\fP(1L) for a more complete description of these modifiers.
.PD
.\" =========================================================================
.SH ENVIRONMENT OPTIONS
\fIunzipsfx\fP uses the same environment variables as \fIunzip\fP(1L) does,
although this is likely to be an issue only for the person creating and
testing the self-extracting archive.  See \fIunzip\fP(1L) for details.
.PD
.\" =========================================================================
.SH DECRYPTION
Decryption is supported exactly as in \fIunzip\fP(1L); that is, interactively
with a non-echoing prompt for the password(s).  See \fIunzip\fP(1L) for 
details.  Once again, note that if the archive has no encrypted files there 
is no reason to use a version of \fIunzipsfx\fP with decryption support;
that only adds to the size of the archive.
.PD
.\" =========================================================================
.SH EXAMPLES
To create a self-extracting archive \fIletters\fP from a regular zipfile 
\fIletters.zip\fP and change the new archive's permissions to be 
world-executable under Unix:
.LP
.PD 0
.Y "cat unzipsfx letters.zip > letters"
.Y "chmod 755 letters"
.PD
.LP
To create the same archive under MS-DOS, OS/2 or NT (note the use of the
\fB/b\fP [binary] option to the \fIcopy\fP command):
.LP
.Y "copy /b unzipsfx.exe+letters.zip letters.exe"
.LP
Under VMS:
.LP
.Y "copy unzipsfx.exe,letters.zip letters.exe"
.Y "letters == ""$currentdisk:[currentdir]letters.exe"""
.LP
(The VMS \fIappend\fP command may also be used.  The second command installs
the new program as a ``foreign command'' capable of taking arguments.)
To test (or list) the newly created self-extracting archive:
.LP
.Y "letters \-t"
.LP
To test \fIletters\fP quietly, printing only a summary message indicating
whether the archive is OK or not:
.LP
.Y "letters \-tq"
.LP
To extract the complete contents into the current directory, recreating all
files and subdirectories as necessary:
.LP
.Y "letters"
.LP
To extract all \fC*.txt\fP files (in Unix quote the `*'):
.LP
.Y "letters *.txt"
.LP
To extract everything \fIexcept\fP the \fC*.txt\fP files:
.LP
.Y "letters * -x *.txt"
.LP
(Note that with regular \fIunzip\fP(1L) it would not be necessary to use 
the first `*'; ``\fCunzip letters -x *.txt\fP'' would work equally well.
With \fIunzipsfx\fP the \fB\-x\fP option would be silently ignored and 
the effect would be the same as in the previous example, i.e., the opposite
of what was intended.)
To extract only the README file to standard output (the screen):
.LP
.Y "letters -c README"
.LP
To print only the zipfile comment:
.LP
.Y "letters \-z"
.PD
.\" =========================================================================
.SH LIMITATIONS
The principle and fundamental limitation of \fIunzipsfx\fP 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, however (e.g., between some flavors of Intel-based Unix).
.LP
\fIunzipsfx\fP 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, \fIunzipsfx\fP 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 which provide the full path name, so the archive may be invoked 
from anywhere in the user's path.  The situation is not known for Atari TOS, 
MacOS, etc.
.LP
As noted above, a number of the normal \fIunzip\fP(1L) functions have
been removed in order to make \fIunzipsfx\fP 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.
.LP
VMS users must know how to set up self-extracting archives as foreign 
commands in order to use any of \fIunzipsfx\fP's options.  This is not
necessary for simple extraction, but the command to do so then becomes,
e.g., ``\fCrun letters\fR'' (to continue the examples given above).
.LP
\fIunzipsfx\fP is not supported on the Amiga because of the way the loader
works; the entire archive contents would be loaded into memory by default.
It may be possible to work around this by defining the attached archive to
be a ``debug hunk,'' but compatibility problems between the ROM levels of
older Amigas and newer ones are likely to cause problems regardless.
.LP
All current bugs in \fIunzip\fP(1L) exist in \fIunzipsfx\fP as well.
.PD
.\" =========================================================================
.SH DIAGNOSTICS
\fIunzipsfx\fP's exit status (error level) is identical to that of
\fIunzip\fP(1L); see the corresponding man page.
.PD
.\" =========================================================================
.SH SEE ALSO
\fIfunzip\fP(1L), \fIunzip\fP(1L), \fIzip\fP(1L), \fIzipcloak\fP(1L),
\fIzipgrep\fP(1L), \fIzipinfo\fP(1L), \fIzipnote\fP(1L), \fIzipsplit\fP(1L)
.PD
.\" =========================================================================
.SH AUTHORS
Greg Roelofs was responsible for the basic modifications to UnZip necessary
to create UnZipSFX.  See \fIunzip\fP(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.
.PD