zip.1

给出了 zip 压缩算法的完整实现过程。

option of \fIzip\fR.
.TP
.B \-g
Grow (append to) the specified
.I zip
archive, instead of creating a new one. If this operation fails,
.I zip
attempts to restore the archive to its original state. If the restoration
fails, the archive might become corrupted. This option is ignored when
there's no existing archive or when at least one archive member must be
updated or deleted.
.TP
.B \-h
Display the
.I zip
help information (this also appears if
.I zip
is run with no arguments).
.TP
.BI \-i\ files
Include only the specified files, as in:
.RS
.IP
\fCzip -r foo . -i \\*.c\fP
.RE
.IP
which will include only the files that end in
.IR \& .c
in the current directory and its subdirectories. (Note for PKZIP
users: the equivalent command is
.RS
.IP
\fCpkzip -rP foo *.c\fP
.RE
.IP
PKZIP does not allow recursion in directories other than the current one.)
The backslash avoids the shell filename substitution, so that the
name matching is performed by
.I zip
at all directory levels.  Not escaping wildcards on shells that do
wildcard substitution before \fIzip\fR gets the command line may seem to
work but files in subdirectories matching the pattern will never be
checked and so not matched.  For shells, such as Win32 command
prompts, that do not replace file patterns containing wildcards
with the respective file names,
.I zip
will do the recursion and escaping the wildcards is not needed.
.IP
Also possible:
.RS
.IP
\fCzip -r foo  . [e-mail]\fP
.RE
.IP
which will only include the files in the current directory and its
subdirectories that match the patterns in the file include.lst, one file
pattern per line.
.TP
.B \-I
[Acorn RISC OS] Don't scan through Image files.  When used,
.I zip
will not
consider Image files (eg. DOS partitions or Spark archives when SparkFS
is loaded) as directories but will store them as single files.
.IP
For example, if you have SparkFS loaded, zipping a Spark archive will result
in a zipfile containing a directory (and its content) while using the 'I'
option will result in a zipfile containing a Spark archive. Obviously this
second case will also be obtained (without the 'I' option) if SparkFS isn't
loaded.
.TP
.B \-j
Store just the name of a saved file (junk the path), and do not store
directory names. By default,
.I zip
will store the full path (relative to the current path).
.TP
.B \-jj
[MacOS] record Fullpath (+ Volname). The complete path including
volume will be stored. By default the relative path will be stored.
.TP
.B \-J
Strip any prepended data (e.g. a SFX stub) from the archive.
.TP
.B \-k
Attempt to convert the names and paths to conform to MSDOS,
store only the MSDOS attribute (just the user write attribute from UNIX),
and mark 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.
.TP
.B \-l
Translate 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 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
.I unzip \-a
on Unix will get back an exact copy of the original file,
to undo the effect of \fIzip \-l\fR.
See the note on binary detection for
.B \-ll
below.
.TP
.B \-ll
Translate the MSDOS end-of-line CR LF into Unix LF.
This option should not be used on binary files and a warning will be
issued when a file is converted that later is detected to be binary.
This option can be used on MSDOS if the zip file is intended for unzip
under Unix.
.IP
In Zip 2.31 and later, binary detection has been changed from a simple
percentage of binary characters being considered binary to a more selective
method that should consider files in many character sets,
including \fIUTF-8\fP, that only include text characters in that character
set to be text.
This allows
.I unzip -a
to convert these files.
.TP
.B \-L
Display the
.I zip
license.
.TP
.B \-m
Move the specified files into the
.I zip
archive; actually,
this deletes the target directories/files after making the specified
.I zip
archive. If a directory becomes empty after removal of the files, the
directory is also removed. No deletions are done until
.I 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
.B \-T
to test the archive before removing all input files.
.TP
.B \-MM
All input patterns must match at least one file and all input files
found must be readable.  Normally when an input pattern does not match
a file the "name not matched" warning is issued and when an input file
has been found but later is missing or not readable a missing or not
readable warning is issued.  In either case
.I zip
continues creating the archive, with missing or unreadable new files
being skipped and files already in the archive remaining unchanged.
After the archive is created, if any files were not readable
.I zip
returns the OPEN error code (18 on most systems) instead of the normal
success return (0 on most systems).  With
.B \-MM
set,
.I zip
exits as soon as an input pattern is not matched (whenever the
"name not matched" warning would be issued) or when an input file is
not readable.  In either case \fIzip\fR exits with an OPEN error
and no archive is created.
.IP
This option is useful when a known list of files is to be zipped so
any missing or unreadable files will result in an error.  It is less
useful when used with wildcards, but \fIzip\fR will still exit with an
error if any input pattern doesn't match at least one file and if any
matched files are unreadable.  If you want to create the archive
anyway and only need to know if files were skipped, don't use
.B \-MM
and just check the return code.
.TP
.BI \-n\ suffixes
Do not attempt to compress files named with the given
\fBsuffixes\fR.
Such files are simply stored (0% compression) in the output zip file,
so that
.I zip
doesn't waste its time trying to compress them.
The suffixes are separated by
either colons or semicolons.  For example:
.RS
.IP
\fCzip -rn .Z:.zip:.tiff:.gif:.snd  foo foo\fP
.RE
.IP
will copy everything from
.I foo
into
.IR foo.zip ,
but will store any files that end in
.IR .Z ,
.IR .zip ,
.IR .tiff ,
.IR .gif ,
or
.I .snd
without trying to compress them
(image and sound files often have their own specialized compression methods).
By default,
.I zip
does not compress files with extensions in the list
.I .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 under Unix with csh:
.RS
.IP
\fCsetenv ZIPOPT "-n .gif:.zip"\fP
.RE
.IP
To attempt compression on all files, use:
.RS
.IP
\fCzip -n : foo\fP
.RE
.IP
The maximum compression option
.B \-9
also attempts compression on all files regardless of extension.
.IP
On Acorn RISC OS systems the suffixes are actually filetypes (3 hex digit
format). By default, zip does not compress files with filetypes in the list
DDC:D96:68E (i.e. Archives, CFS files and PackDir files).
.TP
.B \-N
[Amiga, MacOS] Save Amiga or MacOS filenotes as zipfile comments. They can be
restored by using the
.B \-N
option of unzip. If
.B \-c
is used also, you are prompted for comments only for those files that do not
have filenotes.
.TP
.B \-o
Set the "last modified" time of the
.I zip
archive to the latest (oldest) "last modified" time
found among the entries in the
.I zip
archive.
This can be used without any other operations, if desired.
For example:
.RS
.IP
\fCzip -o foo\fP
.RE
.IP
will change the last modified time of
.I foo.zip
to the latest time of the entries in
.IR foo.zip .
.TP
\fB\-P\fP\ \fIpassword\fP
use \fIpassword\fP to encrypt zipfile entries (if any).  \fBTHIS IS
INSECURE!\fP  Many multi-user operating systems provide ways for any user to
see the current command line of any other user; even on stand-alone systems
there is always the threat of over-the-shoulder peeking.  Storing the plaintext
password as part of a command line in an automated script is even worse.
Whenever possible, use the non-echoing, interactive prompt to enter passwords.
(And where security is truly important, use strong encryption such as Pretty
Good Privacy instead of the relatively weak encryption provided by standard
zipfile utilities.)
.TP
.B \-q
Quiet mode;
eliminate informational messages and comment prompts.
(Useful, for example, in shell scripts and background tasks).
.TP
.BI \-Qn
[QDOS] store information about the file in the file header with n defined as
.RS
bit  0: Don't add headers for any file
.RE
.RS
bit  1: Add headers for all files
.RE
.RS
bit  2: Don't wait for interactive key press on exit
.RE
.TP
.B \-r
Travel the directory structure recursively;
for example:
.RS
.IP
\fCzip -r foo.zip foo\fP
.RE
.IP
or a bit more concisely
.RS
.IP
\fCzip -r foo foo\fP
.RE
.IP
In this case, all the files and directories in
.I foo
are saved in a
.I zip
archive named
.IR 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
.I foo
and its subdirectories, use the
.B \-i
option to specify the pattern of files to be included.
You should not use
.B \-r
with the name ".*",
since that matches ".."
which will attempt to zip up the parent directory
(probably not what was intended).
.TP
.B \-R
Travel the directory structure recursively starting at the
current directory;
for example:
.RS
.IP
\fCzip -R foo '*.c'\fP
.RE
.IP
In this case, all the files matching *.c in the tree starting at the
current directory are stored into a
.I zip
archive named
.IR foo.zip .
Note for PKZIP users: the equivalent command is
.RS
.IP
\fCpkzip -rP foo *.c\fP
.RE
.TP
.B \-S
[MSDOS, OS/2, WIN32 and ATARI] Include system and hidden files.
.RS
[MacOS] Includes finder invisible files, which are ignored otherwise.
.RE
.TP
.BI \-t\ mmddyyyy
Do not operate on files modified prior to the specified date,
where
.I mm
is the month (0-12),
.I dd
is the day of the month (1-31),
and
.I yyyy
is the year.
The
.I ISO 8601
date format
.I yyyy-mm-dd
is also accepted.
For example:
.RS
.IP
\fCzip -rt 12071991 infamy foo\fP
.IP
\fCzip -rt 1991-12-07 infamy foo\fP
.RE
.IP
will add all the files in
.I foo
and its subdirectories that were last modified on or after 7 December 1991,
to the
.I zip
archive
.IR infamy.zip .
.TP
.BI \-tt\ mmddyyyy
Do not operate on files modified after or at the specified date,
where
.I mm
is the month (0-12),
.I dd
is the day of the month (1-31),
and
.I yyyy
is the year.
The
.I ISO 8601
date format
.I yyyy-mm-dd
is also accepted.
For example:
.RS
.IP
\fCzip -rtt 11301995 infamy foo\fP
.IP
\fCzip -rtt 1995-11-30 infamy foo\fP
.RE
.IP
will add all the files in
.I foo
and its subdirectories that were last modified before 30 November 1995,
to the
.I zip
archive
.IR infamy.zip .
.TP
.B \-T
Test the integrity of the new zip file. If the check fails, the old zip file
is unchanged and (with the
.B \-m
option) no input files are removed.
.TP
.B \-u
Replace (update) an existing entry in the
.I zip
archive only if it has been modified more recently
than the version already in the
.I zip
archive.
For example:
.RS
.IP
\fCzip -u stuff *\fP
.RE
.IP
will add any new files in the current directory,
and update any files which have been modified since the
.I zip
archive
.I stuff.zip
was last created/modified (note that
.I zip
will not try to pack
.I stuff.zip
into itself when you do this).
.IP
Note that the
.B \-u
option with no arguments acts like the
.B \-f
(freshen) option.
.TP
.B \-v
Verbose mode or print diagnostic version info.
.IP
Normally, when applied to real operations, this option enables the display of a
progress indicator during compression and requests verbose diagnostic
info about zipfile structure oddities.
.IP
When
.B \-v
is the only command line argument, and either stdin or 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
.I zip
executable.