funzip
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 prefixing the password with a dash.
Note that this constitutes a security risk on many systems; currently
running processes 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 password 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 backups 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
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 funzip 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
directory, 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 20 April 2009 (v3.95) FUNZIP(1L)