aegis -CLone [option...] change-number [change-number]
aegis -CLone -Help
aegis -CLone -VERSion
The
aegis -CLone
command is used to
create exact replicas of changes.
This is of most use when a change need to be applied to several parallel
branches.
One change number must be supplied. This is the change to be replicated. If any branch options are given (see below) the mandatory change number applies to the branch specified. If no branch is specified, the change applies to the project (implicit or explicit).
If the optional second change number is supplied, this is the change number to be created to hold the replica; if it is not supplied, the next available change number will be used.
If the change to be replicated has been completed, the appropriate file revisions will be extracted from history; otherwise the files will be copied from the development directory of the change to be copied. Be warned: if a file in the change which was cloned subsequently changes, those changes will not automagically be tracked. It is best if changes are cloned at a stable time, such as one of the states after develop end, or even after integrate pass.
Please Note: Aegis also consults the underlying file system, to
determine its notion of maximum file size. Where the file system's
maximum file size is less than maximum_filename_length, the
filesystem wins. This can happen, for example, when you are using the
Linux UMSDOS file system, or when you have an NFS mounted an ancient
V7 filesystem. Setting maximum_filename_length to 255 in these
cases does not alter the fact that the underlying file systems limits
are far smaller (12 and 14, respectively).
If your development directories (or your whole project) is on filesystems with filename limitations, or a portion of the heterogeneous builds take place in such an environment, it helps to tell Aegis what they are (using the project config file's fields) so that you don't run into the situation where the project builds on the more permissive environments, but fails with mysterious errors in the more limited environments.
If your development directories are routinely on a Linux
UMSDOS filesystem, you would probably be better off setting
dos_filename_required = true,
and also changing the development_directory_template field.
Heterogeneous development with various Windows environments may
also require this.
Aegis provides you with what is often called a “view path” which indicates to development tools (compilers, build systems, etc) look first in the development directory, then in the branch baseline, and so on up to the trunk baseline.
The problem with view paths is that in order to remove files, you need some kind of "whiteout" to say “stop looking, it's been removed.”
When you user the aerm(1) or aemv(1) commands, this means "add information to this change which will remove the file from the baseline when this change is integrated". I.e. while the change is in the being developed state, the file is only "removed" in the development directory - it's still present in the baseline, and will be until the change is successfully integrated.
When you use the aerm(1) or aemv(1) commands, Aegis will create a 1K file to act as the whiteout. It's contents are rather ugly so that if you compile or include the "removed" file accidentally, you get a fatal error. This will remind you to remove obsolete references.
When the change in integrated, the removed file is not copied/linked from the baseline to the integration directory, and is not copied from the development directory. At this time it is physically gone (no whiteout). It is assumed that because of the error inducing whiteout all old references were found and fixed while the change was in the being developed state.
When generating list of files to be compiled or linked, it is important that the file manifest be generated from information known by Aegis, rather than from the file system. This is for several reasons:
Aegis knows exactly what (source) files are where, whereas everything else is inferring Aegis' knowledge; and
looking in the file system is hard when the view path is longer that 2 directories (and Aegis' branching method can make it arbitrarily long); and
The whiteout files, and anything else left “lying around”, will confuse any method which interrogates the file system.
The easiest way to use Aegis' file knowledge is with something like an awk(1) script processing the Aegis file lists. For example, you can do this with make(1) as follows:
# generate the file manifest
manifest.make.inc: manifest.make.awk
( aegis -l cf -ter ; aegis -l pf -ter ) | \
awk -f manifest.make.awk > manifest.make.inc
# now include the file manifest
include manifest.make.inc
Note: this would be inefficient of you did it once per directory, but there is nothing stopping you writing numerous assignments into the manifest.make.inc file, all in one pass.
It is possible to do the same thing with Aegis' report generator (see aer(1) for more information), but this is more involved than the awk(1) script. However, with the information "straight from the horse's mouth" as it were, it can also be much smarter.
This file manifest would become out-of-date without an interlock to
Aegis' file operations commands. By using the project-file_command
and change_file_command fields of the project config file
(see aepconf(5) for more information), you can delete this file
at strategic times.
/* run when the change file manifest is altered */ change_file_command = "rm -f manifest.make.inc"; /* run when the project file manifest is altered */ project_file_command = "rm -f manifest.make.inc";
The new file manifest will thus be re-built during the next aeb(1) command.
There is a -No-WhiteOut option, which may be used to suppress
whiteout files when you use the aerm(1) and aemv(1) commands.
There is a corresponding -WhiteOut option, which is usually
the default.
There is a whiteout_preference field in the user preferences file
(see aeuconf(5) for more information) if you want to set this
option more permanently.
The whiteout_template field of the project config file may be
used to produce language-specific error files. If no whiteout template
entry matches, a very ugly 1KB file will be produced - it should induce
compiler errors for just about any language.
If you want a more human-readable error message, entries such as
whiteout_template =
[
{
pattern = [ "*.[ch]" ];
body = "#error This file has been removed.";
}
];
can be very effective (this example assumes gcc(1) is being used).
If it is essential that no whiteout file be produced, say for C source files, you could use a whiteout template such as
whiteout_template =
[
{ pattern = [ "*.c" ]; }
];
because an absent body sub-field means generate no whiteout file at all.
You may have more than one whiteout template entry, but note that the order of the entries is important. The first entry which matches will be used.
The notification commands that would be run by the aecp(1),
aedb(1), aenf(1), aent(1) and aerm(1) commands
are run, as appropriate. The project_file_command is also run,
if set. See aepconf(5) for more information.
When you use aeclone(1) to clone a change set, and then integrate one of the two change sets, you will observe that Aegis says that the files of the un-integrated change are now out-of-date.
If you run aem(1) to bring the out-of-date files back up-to-date, fmerge(1) and some (but not) all other merging tools, it signals just about everything as a conflict, even though both alternatives are identical.
The problem is that two changes making identical edits to the same place in the same file are a logical conflict, even if not an actual conflict, and it takes a human to figure out the difference. Think of a shopping list: the ensuite needs more soap, and so does the main bathroom. The second "soap" on the merge of the two shopping lists isn't a duplicate, you really do need two boxes of soap. Sometimes edits of source files are the same: sometimes the logical conflict is resolved by applying both identical edits, not just one.
This is just the fmerge(1) command being more conservative than RCS's merge(1) command.
The easiest way to deal with this common situation it to run an
aecpu -unchanged
file before you run the aem(1) merge command, and you
will have less grief. It's also worth remembering that Aegis stashes
the original file with a ,B suffix (B for backup) so you can
simply
mv fubar,B fubar
if you know that all of the conflicts are logical conflicts.
The following options are understood:
-BRanch numberThis option may be used to specify a
different branch for the origin file,
rather than the baseline.
(See also -TRunk option.\)
Please Note: the -BRanch option does not take a project name,
just the branch number suffix.
-GrandParentThis option may be used to specify the grandparent branch (one up from the current branch) for the origin file, rather than the baseline. (The -grandparent option is the same as the “-branch ..” option.)
-Change numberThis option may be used to specify a particular change within a project. See aegis(1) for a complete description of this option.
-DIRectory pathThis 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.
-HelpThis option may be used to obtain more information about how to use the aegis program.
-ListThis option may be used to obtain a list of suitable subjects for this command. The list may be more general than expected.
-WhiteOutThis option may be used to request that deleted files be replaced by a “whiteout” file in the development directory. The idea is that compiling such a file will result in a fatal error, in order that all references may be found. This is usually the default.
-No_WhiteOutThis option may be used to request that no “whiteout” file be placed in the development directory.
-Output filenameThis option may be used to specify a filename which is to be written with the automatically determined change number. Useful for writing scripts.
-Project nameThis 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.
-TRunkThis option may be used to specify
the project trunk for the origin file,
rather than the baseline.
(See also -BRanch option,
the -trunk option is the same as the “-branch -” option.)
-WaitThis option may be used to require Aegis commands to wait for access
locks, if they cannot be obtained immediately.
Defaults to the user's
lock_wait_preference
if not specified, see
aeuconf(5)
for more information.
-No_WaitThis option may be used to require Aegis commands to emit a fatal error
if access locks cannot be obtained immediately.
Defaults to the user's
lock_wait_preference
if not specified, see
aeuconf(5)
for more information.
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
aegis
are long,
this means ignoring the extra leading '-'.
The "--option=value" convention is also understood.
It is an error if
the current user is not an administrator of the project.
(In some cases it is possible for developers of a project to create
changes,
see
aepattr(5)
for more information.)
The aegis command will exit with a status of 1 on any error. The aegis command will only exit with a status of 0 if there are no errors.
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.
aegis version 4.22 Copyright (C) 1991-2006 Peter Miller; All rights reserved.
The aegis program comes with ABSOLUTELY NO WARRANTY; for details use the 'aegis -VERSion License' command. This is free software and you are welcome to redistribute it under certain conditions; for details use the 'aegis -VERSion License' command.