boinc/zip/unzip/funzip.txt

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FUNZIP(1L) FUNZIP(1L)
NAME
funzip - filter for extracting from a ZIP archive in a
pipe
SYNOPSIS
funzip [-password] [input[.zip|.gz]]
ARGUMENTS
[-password]
Optional password to be used if ZIP archive is
encrypted. Decryption may not be supported at some
sites. See DESCRIPTION for more details.
[input[.zip|.gz]]
Optional input archive file specification. See
DESCRIPTION for details.
DESCRIPTION
funzip without a file argument acts as a filter; that is,
it assumes that a ZIP archive (or a gzip'd(1) file) is
being piped into standard input, and it extracts the first
member from the archive to stdout. When stdin comes from
a tty device, funzip assumes that this cannot be a stream
of (binary) compressed data and shows a short help text,
instead. If there is a file argument, then input is read
from the specified file instead of from stdin.
A password for encrypted zip files can be specified on the
command line (preceding the file name, if any) by prefix-
ing the password with a dash. Note that this constitutes
a security risk on many systems; currently running pro-
cesses are often visible via simple commands (e.g., ps(1)
under Unix), and command-line histories can be read. If
the first entry of the zip file is encrypted and no pass-
word is specified on the command line, then the user is
prompted for a password and the password is not echoed on
the console.
Given the limitation on single-member extraction, funzip
is most useful in conjunction with a secondary archiver
program such as tar(1). The following section includes an
example illustrating this usage in the case of disk back-
ups to tape.
EXAMPLES
To use funzip to extract the first member file of the
archive test.zip and to pipe it into more(1):
funzip test.zip | more
To use funzip to test the first member file of test.zip
(any errors will be reported on standard error):
funzip test.zip > /dev/null
Info-ZIP 17 February 2002 (v3.94) 1
FUNZIP(1L) FUNZIP(1L)
To use zip and funzip in place of compress(1) and zcat(1)
(or gzip(1L) and gzcat(1L)) for tape backups:
tar cf - . | zip -7 | dd of=/dev/nrst0 obs=8k
dd if=/dev/nrst0 ibs=8k | funzip | tar xf -
(where, for example, nrst0 is a SCSI tape drive).
BUGS
When piping an encrypted file into more and allowing fun-
zip to prompt for password, the terminal may sometimes be
reset to a non-echo mode. This is apparently due to a
race condition between the two programs; funzip changes
the terminal mode to non-echo before more reads its state,
and more then ``restores'' the terminal to this mode
before exiting. To recover, run funzip on the same file
but redirect to /dev/null rather than piping into more;
after prompting again for the password, funzip will reset
the terminal properly.
There is presently no way to extract any member but the
first from a ZIP archive. This would be useful in the
case where a ZIP archive is included within another
archive. In the case where the first member is a direc-
tory, funzip simply creates the directory and exits.
The functionality of funzip should be incorporated into
unzip itself (future release).
SEE ALSO
gzip(1L), unzip(1L), unzipsfx(1L), zip(1L), zipcloak(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/ .
AUTHOR
Mark Adler (Info-ZIP)
Info-ZIP 17 February 2002 (v3.94) 2