Ubuntu Manpage: aetar - remotely distribute a change via tar

NAME

        aetar - remotely distribute a change via tar

SYNOPSIS

        aetar -Send [ option...  ]
        aetar -Receive [ option...  ]
        aetar -List [ option...  ]
        aetar -Help
        aetar -VERSion

DESCRIPTION

        The  aetar  command  is  used  to  send  and receive change sets via tar(1) to facilitate geographically
        distributed development.

        The basic function is to reproduce a change, so a command like
                aetar -send | aetar -receive
        may be used to clone a change, though less efficiently than aeclone(1).  The  file  format  used  is  an
        ordinary gzip(1) compressed tar(1) archive.

SEND

The send variant takes a specified change, or baseline, and constructs a distribution package containing
all of the source file contents. No change meta-data is included.

It is not necessary for the recipient to have the aetar(1) command. It is possible to use the regular
tar xzf command to extract the files from the archive.

Options
The following options are understood by the send variant:

-BaseLine
This option may be used to specify the source of a project, rather than a change.

-Add_Path_Prefix string
This option may be used to specify a path prefix to be added to every filename in the archive.
This means that when the archive is unpacked, it will all be placed in the one directory.

-Change number
This option may be used to specify a particular change within a project. See aegis(1) for a
complete description of this option.

-COMPATibility version-number
This option may be used to specify the version of aetar(1) which will be receiving this change
set. This information is used to select which features to include in the data, and which to
omit. By default, the latest feature set will be used.

-compression-algorithm name
This option may be used to specify the compression to be used. They are listed on order of
compression effeciency.

none Use no compression (not always meaningful for all commands).

gzip Use the compression used by the gzip(1) program.

bzip2 Use the compression used by the bzip2(1) program.

More compression algorithms may be added in the future.

-COMPress
This option is deprecated in favour of the -comp-alg=gzip or -comp-alg=bzip2 options.

-No_COMPress
This options is deprecated in favour of the -comp-alg=none option.

-DELta number
This option may be used to specify a particular delta in the project's history to copy the file
from, rather than the most current version. If the delta has been given a name (see aedn(1) for
how) you may use a delta name instead of a delta number. It is an error if the delta specified
does not exist. Delta numbers start from 1 and increase; delta 0 is a special case meaning
“when the branch started”.

-DELta_Date string
This option may be used to specify a particular date and time in the project's history to copy
the file from, rather than the most current version. It is an error if the string specified
cannot be interpreted as a valid date and time. Quote the string if you need to use spaces.

-DELta_From_Change number
This option may be used to specify a particular project delta from its change number.

-Entire_Source
This option may be used to send the entire source of the project, as well as the change source
files. This is the default.

-Partial_Source
This option may be used to send only source files of a change.

-Include_Build
This option may be used to send also build files.

-Not_Include_Build
This option may be used to send only source (source, test, config but not build) files. This is
the default.

-Output filename
This option may be used to specify the output file. The output is sent to the standard output
by default.

-Project name
This option may be used to select the project of interest. When no -Project option is
specified, the AEGIS_PROJECT environment variable is consulted. If that does not exist, the
user's $HOME/.aegisrc file is examined for a default project field (see aeuconf(5) for more
information). If that does not exist, when the user is only working on changes within a single
project, the project name defaults to that project. Otherwise, it is an error.

RECEIVE

The receive variant takes a tarball and creates an Aegis change (see aenc(1)) to implement the change
within. Files are added to the change (see aenf(1), aecp(1), aerm(1), aent(1)) and then the file
contents are unpackaged into the development directory.

It is not necessary for the sender to have the aetar(1) command. It is possible to use the regular tar
czf command to create the the tarball. You may want to use the tardy(1) command to manipulate the
filenames before extraction.

File Names
It is common for tar files generated to distribute open source projects to contain a path prefix.

-Remove_Path_Prefix string
This option may be used to explicitly specify path prefixes to be removed, if present. It may
be specified more than once.

-Remove_Path_Prefix number
Strip the smallest prefix containing num leading slashes from each file name found in the patch
file. A sequence of one or more adjacent slashes is counted as a single slash.

If you have a complex project directory structure, from time to time people may send you tarballs
relative to a sub-directory, rather than relative to the project root.

-Add_Path_Prefix string
This option may be used to specify the path of a project sub-directory in which to apply the
tarball.

Notification
The aetar command invokes various other Aegis commands. The usual notifications that these commands
would issue are issued.

Options
The following options are understood by the receive variant:

-Change number
This option may be used to choose the change number to be used, otherwise one will be chosen
automatically.

-DELta number
This option may be used to specify a particular delta in the project's history to copy the file
from, just as for the aecp(1) command. You may also use a delta name instead of a delta number.

-DIRectory path
This option may be used to specify which directory is to be used. It is an error if the current
user does not have appropriate permissions to create the directory path given. This must be an
absolute path.

Caution: If you are using an automounter do not use `pwd` to make an absolute path, it usually
gives the wrong answer.

-EXCLude
This option may be used to exclude certain files in the tarball from consideration.

You can also add more exclusions using the project_specific field of the project configuration,
using the aetar:exclude attribute listing file names to exclude separated by spaces.

-Exclude_Auto_Tools
This option may be used to exclude files common to tarballs of open source projects which used
GNU Autoconf or GNU Automake. This is triggered by the presence of configure.ac, configure.in
or Makefile.am files. This only works for simple projects, more complex projects will need to
use the project exclude attributes.

You can set this automatically using the boolean aetar:exclude-auto-tools attribute in the
project_specific field of the project configuration file.

-Exclude_CVS
This option may be used to exclude files common to CVS repositories, which implement the
repository functions, rather than contain source code. It will also look inside .cvsignore
files for additional files to ignore.

You can set this automatically using the boolean aetar:exclude-cvs attribute in the project_‐
specific field of the project configuration file.

-File filename
Read the change set from the specified file. The default is to read it from the standard input.
The filename `-' is understood to mean the standard input.

If your system has libcurl(3), and Aegis was configured to use it at compile time (this is the
default if it is available) you will also be able to specify a Uniform Resource Locator (URL) in
place of the file name. The relevant data will be downloaded. (The -Verbose option will
provide a progress bar.)

-Trojan This option may be used to treat the change set as if it had a Trojan horse attack in it.

-No_Trojan
This option may be used to treat the change set as if it definitely does not have a Trojan horse
attack in it. Use with extreme care. You need to have authenticated the message with something
like PGP first and know the the author well.

Security
Downloading a tarball and automatically committing it to the baseline without checking it would be a
recipe for disaster. A number of safeguards are provided:

• The file sare unpacked into a new change. You need to edit the change description. You need to
uncopy unchanged files. You need to difference the change. You need to build and test the change.
This ensures that a local reviewer validates the change before it is committed, preventing accidental
or malicious damage.

• The use of authentication and encryption systems, such as PGP and GPG, are encouraged. However, it is
expected that this processing will occur after aetar --send has constructed the package and before
aetar --receive examines and acts on the package. Verification of the sender is the surest defense
against trojan horses.

• Automatic sending and receiving of packages is supported, but not implemented within the aetar
command. It is expected that the aetar command will be used within shell scripts customized for your
site and its unique security requirements. See the Aegis User Guide for several different ways to do
this.

• The more you use Aegis' test management facilities (see aent(1) and aet(1)) the harder it is for an
inadequate change to get into the baseline.

LIST

        The list variant can be used to list the contents of a tarball without actually unpacking it first.

   Options
        The following options are understood by the list variant:

        -File filename
                Read the change set from the specified file.  The default is to read it from the standard input.
                The filename `-' is understood to mean the standard input.

                If  your  system has libcurl(3), and Aegis was configured to use it at compile time (this is the
                default if it is available) you will also be able to specify a Uniform Resource Locator (URL) in
                place of the file name.  The relevant data  will  be  downloaded.   (The  -Verbose  option  will
                provide a progress bar.)

        -Output filename
                This  option  may be used to specify the output file.  The output is sent to the standard output
                by default.  Only useful with the -List option.

OPTIONS

        The following options to this command haven't been mentioned yet:

        -Help
                This option may be used to obtain more information about how to use the aetar program.

        See also aegis(1) for options common to all aegis commands.

        All options may be abbreviated; the abbreviation is documented as the upper case letters, all lower case
        letters and underscores (_) are optional.  You must use consecutive sequences of optional letters.

        All options are case insensitive, you may type them in upper case or lower  case  or  a  combination  of
        both, case is not important.

        For  example: the arguments "-project, "-PROJ" and "-p" are all interpreted to mean the -Project option.
        The argument "-prj" will not be understood, because consecutive optional characters were not supplied.

        Options and other command line arguments may be  mixed  arbitrarily  on  the  command  line,  after  the
        function selectors.

        The  GNU  long  option  names  are  understood.   Since  all option names for aetar are long, this means
        ignoring the extra leading '-'.  The "--option=value" convention is also understood.

FILE FORMAT

        The file format re-uses existing formats, rather than introduce anything new.  This means it is possible
        to extract the contents of a package even when aetar is unavailable.

        • The source files and other information is stored as a normal Unix tar(1) archive.

        • On sending, the tarball is compressed using the GNU gzip format.  Typically primary source  files  are
          ASCII text, resulting in significant compression.  (This is optional.)
          On  receiving,  if  the  tarball  is  compressed  it  will be automagically uncompressed, detection is
          automatic, you do not need to do this yourself.

EXIT STATUS

        The aetar command will exit with a status of 1 on any error.  The aetar command will only  exit  with  a
        status of 0 if there are no errors.

ENVIRONMENT VARIABLES

        See  aegis(1) for a list of environment variables which may affect this command.  See aepconf(5) for the
        project configuration file's project_specific field  for  how  to  set  environment  variables  for  all
        commands executed by Aegis.

COPYRIGHT

        aetar version 4.24.3.D001
        Copyright  (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
        2006, 2007, 2008, 2009, 2010 Peter Miller

        The aetar program comes with ABSOLUTELY NO WARRANTY;  for  details  use  the  'aetar  -VERSion  License'
        command.   This  is  free  software and you are welcome to redistribute it under certain conditions; for
        details use the 'aetar -VERSion License' command.

AUTHOR

        Peter Miller   E-Mail:   millerp@canb.auug.org.au
        /\/\*             WWW:   http://www.canb.auug.org.au/~millerp/

Reference Manual                                      Aegis                                             aetar(1)