zipinfo.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.
.\"
.\" zipinfo.1 by Greg Roelofs and others.
.\"
.\" =========================================================================
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.\" =========================================================================
.TH ZIPINFO 1L "28 Aug 94 (v2.02)"
.SH NAME
zipinfo \- list detailed information about a ZIP archive
.PD
.\" =========================================================================
.SH SYNOPSIS
\fBzipinfo\fP [\fB\-12smlvhtTz\fP] \fIfile\fP[\fI.zip\fP]
[\fIfile(s)\fP\ .\|.\|.] [\fB\-x\fP\ \fIxfile(s)\fP\ .\|.\|.]
.LP
\fBunzip\fP \fB\-Z\fP [\fB\-12smlvhtTz\fP] \fIfile\fP[\fI.zip\fP]
[\fIfile(s)\fP\ .\|.\|.] [\fB\-x\fP\ \fIxfile(s)\fP\ .\|.\|.]
.PD
.\" =========================================================================
.SH DESCRIPTION
\fIzipinfo\fP lists technical information about files in a ZIP archive, most
commonly found on MS-DOS systems.  Such information includes file access
permissions, encryption status, type of compression, version and operating
system or file system of compressing program, and the like.  The default
behavior (with no options) is 
to list single-line entries for each file in the archive, with header and
trailer lines providing summary information for the entire archive.  The
format is a cross between Unix ``\fCls \-l\fR'' and ``\fCunzip \-v\fR''
output.  See
.B DETAILED DESCRIPTION
below.  Note that \fIzipinfo\fP is the same program as \fIunzip\fP (under
Unix, a link to it); on some systems, however, \fIzipinfo\fP support may 
have been omitted when \fIunzip\fP was compiled.
.PD
.\" =========================================================================
.SH ARGUMENTS
.TP
.IR file [ .zip ]
Path of the ZIP archive(s).  If the file specification is a wildcard,
each matching file is processed in an order determined by the operating
system (or file system).  Only the filename can be a wildcard; the path
itself cannot.  Wildcard expressions are similar to Unix \fIegrep\fP(1)
(regular) expressions and 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.)  If no
matches are found, the specification is assumed to be a literal filename; 
and if that also fails, the suffix \fC.zip\fP is appended.  Note that 
self-extracting ZIP files are supported; just specify the \fC.exe\fP suffix
(if any) explicitly.
.IP [\fIfile(s)\fP]
An optional list of archive members to be processed.
Regular expressions (wildcards) may be used to match multiple members; see
above.  Again, be sure to quote expressions that would otherwise be expanded
or modified by the operating system.
.IP [\fB\-x\fP\ \fIxfile(s)\fP]
An optional list of archive members to be excluded from processing.
.\" =========================================================================
.SH OPTIONS
.TP
.B \-1
list filenames only, one per line.  This option excludes all others; headers,
trailers and zipfile comments are never printed.  It is intended for use in
Unix shell scripts.
.TP
.B \-2
list filenames only, one per line, but allow headers (\fB\-h\fP), trailers
(\fB\-t\fP) and zipfile comments (\fB\-z\fP), as well.  This option may be
useful in cases where the stored filenames are particularly long.
.TP
.B \-s
list zipfile info in short Unix ``\fCls \-l\fR'' format.  This is the default
behavior; see below.
.TP
.B \-m
list zipfile info in medium Unix ``\fCls \-l\fR'' format.  Identical to the
\fB\-s\fP output, except that the compression factor, expressed as a
percentage, is also listed.
.TP
.B \-l
list zipfile info in long Unix ``\fCls \-l\fR'' format.  As with \fB\-m\fP 
except that the compressed size (in bytes) is printed instead of the 
compression ratio.
.TP
.B \-v
list zipfile information in verbose, multi-page format.
.TP
.B \-h
list header line.  The archive name, actual size (in bytes) and total number
of files is printed.
.TP
.B \-t
list totals for files listed or for all files.  The number of files listed,
their uncompressed and compressed total sizes, and their overall compression
factor is printed; or, if only the totals line is being printed, the values
for the entire archive are given.  Note that the total compressed (data)
size will never match the actual zipfile size, since the latter includes all
of the internal zipfile headers in addition to the compressed data.
.TP
.B \-T
print the file dates and times in a sortable decimal format (yymmdd.hhmmss).
The default date format is a more standard, human-readable version with
abbreviated month names (see examples below).
.TP
.B \-z
include the archive comment (if any) in the listing.
.PD
.\" =========================================================================
.SH DETAILED DESCRIPTION
.I zipinfo
has a number of modes, and its behavior can be rather difficult to fathom
if one isn't familiar with Unix \fIls\fP(1) (or even if one is).  The default
behavior is to list files in the following format:
.LP
.X "-rw-rws---  1.9 unx    2802 t- defX 11-Aug-91 13:48 perms.2660"
.LP
The last three fields are the modification date and time of
the file, and its name.  The case of the filename is respected; thus
files which come from MS-DOS PKZIP are always capitalized.  If the file
was zipped with a stored directory name, that is also displayed as part
of the filename.
.LP
The second and third fields indicate that the file was zipped under
Unix with version 1.9 of \fIzip\fP.  Since it comes from Unix, the file
permissions at the beginning of the line are printed in Unix format.
The uncompressed file-size (2802 in this example) is the fourth field.
.LP
The fifth field consists of two characters, either of which may take
on several values.  The first character may be either `t' or `b', indicating
that \fIzip\fP believes the file to be text or binary, respectively;
but if the file is encrypted, \fIzipinfo\fP
notes this fact by capitalizing the character (`T' or `B').  The second
character may also take on four values, depending on whether there is
an extended local header and/or an ``extra field'' associated with the
file (fully explained in PKWare's APPNOTE.TXT, but basically analogous to 
pragmas in ANSI C--i.e., they provide a standard way to include non-standard 
information in the archive).  If neither exists, the character
will be a hyphen (`\-'); if there is an extended local header but no extra
field, `l'; if the reverse, `x'; and if both exist, `X'.  Thus the
file in this example is (probably) a text file, is not encrypted, and
has neither an extra field nor an extended local header associated with it.
The example below, on the other hand, is an encrypted binary file with an 
extra field:
.LP
.X "RWD,R,R     0.9 vms     168 Bx shrk  9-Aug-91 19:15 perms.0644"
.LP
Extra fields are used for various purposes (see discussion of the \fB\-v\fP
option below) including the storage of VMS file attributes, which is 
presumably the case here.  Note that the file attributes are listed in
VMS format.  Some other possibilities for the host operating system (which
is actually a misnomer--host file system is more correct) include
OS/2 or NT with High Performance File System (HPFS), MS-DOS, OS/2 or NT
with File Allocation Table (FAT) file system, and Macintosh.  These are
denoted as follows:
.LP
.X "-rw-a--     1.0 hpf    5358 Tl i4:3  4-Dec-91 11:33 longfilename.hpfs"
.X "-r--ahs     1.1 fat    4096 b- i4:2 14-Jul-91 12:58 EA DATA. SF"
.X "--w-------  1.0 mac   17357 bx i8:2  4-May-92 04:02 unzip.macr"
.LP
File attributes in the first two cases are indicated in a Unix-like format,
where the seven subfields indicate whether the file:  (1) is a directory,
(2) is readable (always true), (3) is writable, (4) is executable (guessed 
on the basis of the extension--\fI.exe\fP, \fI.com\fP, \fI.bat\fP, \fI.cmd\fP
and \fI.btm\fP files are assumed to be so), (5) has its archive bit set, 
(6) is hidden, and (7) is a system file.  Interpretation of Macintosh file 
attributes is unreliable because some Macintosh archivers don't store any
attributes in the archive.
.LP
Finally, the sixth field indicates
the compression method and possible sub-method used.  There are six methods
known at present:  storing (no compression), reducing, shrinking, imploding,
tokenizing (never publicly released), and deflating.  In addition, there are 
four levels of reducing (1 through 4); four types of imploding (4K or 8K 
sliding dictionary, and 2 or 3 Shannon-Fano trees); and four levels of 
deflating (superfast, fast, normal, maximum compression).  \fIzipinfo\fP
represents these methods and their sub-methods as follows:  \fIstor\fP;
\fIre:1\fP, \fIre:2\fP, etc.; \fIshrk\fP; \fIi4:2\fP, \fIi8:3\fP, etc.;
\fItokn\fP; and \fIdefS\fP, \fIdefF\fP, \fIdefN\fP, and \fIdefX\fP.
.LP
The medium and long listings are almost identical to the short format except 
that they add information on the file's compression.  The medium format lists 
the file's compression factor as a percentage indicating the amount of space