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.

-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

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:	pmiller@opensource.org.au
/\/\*	WWW:	http://miller.emu.id.au/pmiller/