xenial (1) guncat.1.gz

Provided by: guncat_1.01.02-1_amd64 bug

NAME

       guncat - catenates files, unencrypting pgp encrypted sections

SYNOPSIS

       guncat [OPTIONS] [file(s)]
       [OPTIONS] - cf. section OPTIONS
       [file(s)] - optional files to process (cf. section INPUT FILE(S))

DESCRIPTION

       Guncat  was  designed to tackle a problem encountered with (partically) PGP encrypted files (which may be
       encountered in, e.g., mailboxes). Tools to process text-files (like grep(1), or less(1)) may be  used  to
       process those files, but standard tools like cat(1) leave PGP encrypted sections within such files as-is.
       As a consequence, browsing the `real’ contents (i.e., clear-text sections and the unencrypted contents of
       PGP encrypted sections) of those files is difficult.

       Guncat  acts  like  cat,  but unencrypts encrypted sections encountered in the files processed by guncat,
       copying the unencrypted information to guncat’s standard output stream, which may thereupon be  processed
       by other tools.

       PGP/GPG encrypted sections are surrounded by


       -----BEGIN PGP MESSAGE-----
       and


       -----END PGP MESSAGE-----
       markers.  Whenever  guncat  encounters  such  sections  they  will  be  processed  by gpg(1). Gpg needs a
       passphrase to unencrypt such sections. The required passphrase may be provided to guncat, which will then
       forward the passphrase to gpg, or gpg will itself ask for the required passphrase.

       When  providing  an  incorrect  passphrase  to  guncat  two  additional  attempts  to provide the correct
       passphrase are granted. If the  third  attempt  also  fails,  guncat  terminates.  Furthermore,  when  an
       incorrect  passphrase  is  provided,  the  currently processed file must be reset to the beginning of the
       encrypted section. This implies that the processed file must be seekable. If the file  does  not  support
       seeking operations then guncat also terminates.

RETURN VALUE

       Guncat  returns  0  to  the  operating  system unless an error occurs (0 is also returned when usage info
       (option --help), guncat’s  version  number  (option  --version),  or  the  configured  gpg  call  (option
       --show-gpg) is requested.

INPUT FILE(S)

       When  no file arguments are provided (or when - is provided) the standard input stream is processed. Note
       that when the standard input stream is specified and option --passphrase is specified the standard  input
       stream’s first line is used as gpg’s passphrase.

       Any  other argument is considered a file (path specifications are allowed) to be processed in sequence by
       guncat.

       If an argument does not refer to a readable file, guncat terminates with an error message.

OPTIONS

       Where available, single  letter  options  are  listed  between  parentheses  following  their  associated
       long-option  variants.  Single  letter options require arguments if their associated long options require
       arguments as well.

       o      --gpg=path
              Path to the gpg program (default: /usr/bin/gpg)

       o      --gpg-msg=path (-m)
              Path to where gpg should write its messages. Specify - to write the messages to the standard error
              stream. By default messages are suppressed.

       o      --gpg-no-batch
              Option --batch is omitted when calling gpg.

       o      --gpg-option=option (-m)
              Add  option  to  gpg’s  call.  If  the option contains blanks, surround option by single or double
              quotes.

       o      --help (-h)
              Basic usage information is written to the standard output stream.

       o      --locate-keys -l
              Locate missing public keys at the configured key  server(s)  (by  default  missing  keys  are  not
              searched for).

       o      --passphrase -p
              The  passphrase  is  read as the first line from the standard input stream (without being echoed);
              otherwise the passphrase is handled by gpg itself (e.g., using gpg-agent(1)).

       o      --show-gpg
              Show the gpg command that would be used, and quit, returning 0.

       o      --tty-OK -t
              Option --no-tty is omitted when calling gpg.

       o      --verbose=[0-2]
              Specifies gpg’s verbosity level. When calling gpg, by default --quiet is specified; with --verbose
              0 gpg’s option --no-verbose is specified; otherwise --verbose is specified once or twice.

       o      --version (-v)
              Guncat’s version number is written to the standard output stream.

SEE ALSO

       cat(1), gpg(1), gpg-agent(1), grep(1), less(1).

BUGS

       None reported

       This is free software, distributed under the terms of the `GNU General Public License’. Copyright remains
       with the author. Guncat is available at https://fbb-git.github.io/guncat/

ORGANIZATION

       Center for Information Technology, University of Groningen.

AUTHOR

           Frank B. Brokken (f.b.brokken@rug.nl).