NAME
aerevml - send and receive RevML change sets
SYNOPSIS
aerevml -Send [ option... ]
aerevml -Receive [ option... ]
aerevml -Help
aerevml -VERSion
DESCRIPTION
The aerevml command is used to send and receive change sets using the
RevML format. This format is independent of any particular VC/SCM tool
or vendor. It allows export from any RevML capable VC/SCM system and
import into any other RevML capable VC/SCM system.
The basic function is to reproduce a change, so a command like
aerevml -send | aerevml -receive
may be used to clone a change, though less efficiently than aeclone(1).
The file format used is designed to withstand mail servers, so
activities such as
aerevml -send | e-mail | aerevml -receive
(where e-mail represents sending, transporting and receiving your e-
mail) will reproduce the change on a remote system. With suitable
tools (such as PGP) is it possible to
aerevml -send | encrypt | e-mail | decrypt | aerevml -receive
The mechanism is also designed to allow web-based distribution such as
aerevml -send | web-server web-browser | aerevml -receive
by the use of appropriate CGI scripts and mailcap entries.
It is possible to support both a “push” model and a “pull” model using
this command. For suggestions and ideas for various ways to do this,
see the Aegis Users Guide.
RevML Project
The RevML format is used for copying revision controlled files and
change sets between various SCM repositories. The RevML project may be
found at http://public.perforce.com/public/revml/index.html
The latest RevML DTD may be found at http://public.perforce.com/‐
public/revml/revml.dtd
SEND
The send variant takes a specified change, or baseline, and constructs
a distribution package containing all of the change attributes and
source file attributes and source file contents. The result is
compressed, and encoded into a text format which can be sent as e-mail
without being corrupted by the mail transfer agents along the way.
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. Implies the -Entire_Source option,
unless over-ridden.
-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 aerevml(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.
-Content_Transfer_Encoding name
This option may be used to specify the content transfer
encoding to be used. It may take one of the following values:
None No content transfer encoding is to be performed.
Base64 The MIME base 64 encoding is to be used. This is the
default.
Quoted_Printable
The MIME quoted printable encoding is to be used.
Unix_to_Unix_encode
The ancient unix-to-unix encoding is to be used.
These encodings may be abbreviated in the same way as comment
line options.
-Ascii_Armor
This means the same as the “-cte=base64” option above.
-No_Ascii_Armor
This means the same as the “-cte=none” option above.
-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.
-Description_Header
This option may be used to add an RFC 822 style header to the
change description being sent, with a From and Date line. This
is the default.
-No_Description_Header
This option suppresses the description header.
-Entire_Source
This option may be used to send the entire source of the
project, as well as the change source files.
-Mime_Headers
This option may be use to force the presence of mime headers in
the output, in circumstances they would usually be absent.
-No_Mime_Headers
This option may be use to force the absence of mime headers in
the output, in circumstances where they would usually be
present.
-Partial_Source
This option may be used to send only source files of a change.
This is the default, except for the -BaseLine option.
-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.
-Signed_Off_By
This option may be used to have a Signed-off-by: line appended
to the change set description.
-No_Signed_Off_By
This option may be used to prevent a Signed-off-by: line from
being appended to the change set description.
RECEIVE
The receive variant takes a change package created by the send variant
and creates an Aegis change (see aenc(1)) to implement the change
within. Files are added to the change (see aerm(1), aecp(1), aenf(1)
and aent(1)) and then the file contents are unpackaged into the
development directory.
The change is then built (see aeb(1)), differenced (see aed(1)), and
tested (see aet(1)). If all of this is successful, development of the
change is ended (see aed(1)). The automatic process stops at this
point, so that a local reviewer can confirm that the change is desired.
Notification
The aerevml 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.
-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.)
-Ignore_UUID
This option may be used to ignore the UUID, if present, of the
incoming change set.
-No_Ignore_UUID
This option force the aerevml command to use the change set’s
UUID. This is the default.
-Project name
This option may be used to set the project name. If not
specified, the project name in the input package will be used,
rather than the usual project name defaulting mechanism.
-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
Receiving changes by e-mail, and automatically committing them to the
baseline without checking them, would be a recipe for disaster. A
number of safeguards are provided:
· The format of the package is confirmed to be correct, and the package
verified for internal consistency, before it is unpacked and acted
upon.
· The automatic portion of the process stops when development ends.
This ensures that a local reviewer validates the change before it is
committed, preventing accidental or malicious damage.
· If the change seeks to update the project config file, the automatic
process terminates before the build or difference occurs. This is
because this file could contain trojans for these operations, so a
human must examine the file before the change proceeds any further.
· There is a potential_trojan_horse = [ string ]; field in the
projectconfig file. Nominate build configuration files, shell
scripts, code generators, etc here to specify files in addition to
the project configuration file which should cause the automatic
processing to halt.
· The use of e-mail authentication and encryption systems, such as PGP
and GPG, are encouraged. However, it is expected that this
processing will occur after aerevml --send has constructed the
package and before aerevml --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 aerevml command. It is expected that the
aerevml 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.
Duplicate Storms
In a distributed development environment, it is common for change sets
to eventually be propagated back to the originator. There are
situations (particularly in some star topologies) where several copies
of the package will return to the originator.
If these change sets are not detected at the review stage, and are
propagated out yet again, there is the possibility of an exponential
explosion of redundant change sets being distributed again and again.
To combat this, changes are checked after the files are unpacked, but
before and build or difference or test is performed. The “aecpu
--unchanged” command is used to exclude all files that the local
repository already has in the desired form. If no change files remain
after this, the change is dropped entirely (see aedbu(1) and aencu(1)).
LIST
The list variant can be used to list the contents of a package without
actually unpacking it first. The output is reminiscent of the aegis
-list change-details output.
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 aerevml 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
aerevml are long, this means ignoring the extra leading ’-’. The
"--option=value" convention is also understood.
EXIT STATUS
The aerevml command will exit with a status of 1 on any error. The
aerevml 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
aerevml 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 aerevml program comes with ABSOLUTELY NO WARRANTY; for details use
the ’aerevml -VERSion License’ command. This is free software and you
are welcome to redistribute it under certain conditions; for details
use the ’aerevml -VERSion License’ command.
AUTHOR
Peter Miller E-Mail: millerp@canb.auug.org.au
/\/\* WWW: http://www.canb.auug.org.au/~millerp/