Provided by: guncat_1.02.00-2build1_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 (partially) 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 comparably to 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 then forwards the passphrase to gpg.

       When providing an incorrect passphrase to guncat two additional attempts  to  provide  the
       correct  passphrase  are  provided.  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
       the option --show-gpg) is specified.

INPUT FILE(S)

       When no file arguments are provided (or when - is provided) the standard input  stream  is
       processed.

       When  option  --passphrase is specified the first line of the first file that is processed
       is read as the passphrase to use. When a thus specified passphrase  is  incorrect,  guncat
       terminates.

       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      --errors-OK
              When specifying the option --errors-OK the input s continue to be processed even if
              gpg returns a non-zero exit value.

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

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

       o      --gpg-no-batch
              Starting with guncat version 1.02.00 this option is not used anymore.  It  will  be
              removed in a future vestion.

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

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

       o      --locate-keys -l
              Starting with gpg version 1.02.00 this option is  not  used  anymore.  It  will  be
              removed in a future vestion.

       o      --passphrase -p
              By  default  the passphrase is read by guncat after prompting the user to enter the
              passphrase. The passphrase is not echoed. If input redirection is used or if  input
              files  are  specified  option  --passphrase can be specified to read the passphrase
              from the first line of the first input stream that is read by guncat. In that  case
              the input stream’s first line is (of course) not written to the output stream. When
              the --passphrase option is specified and the provided password is incorrect, guncat
              terminates.

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

       o      --time-limit=seconds (-T)
              Option --time-limit is used to specify the max. time in seconds that gpg is allowed
              to run while decrypting a single encrypted section. By default  no  time  limit  is
              used.  This  option  is  useful  when  the  file to process might contain errors in
              encrypted sections (like a missing END PGP MESSAGE line).

       o      --tty-OK -t
              Option --no-tty is not specified when calling gpg. By default it is specified.

       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), grep(1), less(1).

BUGS

       None reported

COPYRIGHT

       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.gitlab.io/guncat/

ORGANIZATION

       Center for Information Technology, University of Groningen.

AUTHOR

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