Date: Thu, 31 Jul 1997 20:30:13 +0530 From: A Joseph Koshy <koshy@india.hp.com> To: phk@freebsd.org, freebsd-doc@freebsd.org Subject: Update to CTM tutorial Message-ID: <199707311502.IAA09373@palrel3.hp.com>
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Hi,
I found the CTM tutorial in the Handbook a bit dated so I've done the
needful and added a new section to it while at the job. Could someone
please commit this?
Koshy
<koshy@india.hp.com> My Personal Opinions Only.
Index: ctm.sgml
===================================================================
RCS file: /usr/cvs/doc/handbook/ctm.sgml,v
retrieving revision 1.19
diff -u -r1.19 ctm.sgml
--- ctm.sgml 1997/06/02 16:42:21 1.19
+++ ctm.sgml 1997/07/31 15:32:59
@@ -16,7 +16,7 @@
<sect1><heading>CTM<label id="ctm"></heading>
-<p><em>Contributed by &a.phk;. Updated 16-Mar-1995.</em>
+<p><em>Contributed by &a.phk;. Updated 31-July-1997.</em>
<tt/CTM/ is a method for keeping a remote directory tree in sync with a
central one. It has been developed for usage with FreeBSD's source
@@ -108,11 +108,13 @@
all deltas with higher numbers following it.
<sect2><heading>Using <tt/CTM/ in your daily life</heading>
- <p>To apply the deltas, simply say
- <verb>
- cd /where/ever/you/want/the/stuff
- ctm -v -v /where/you/store/your/deltas/src-cur.*
- </verb>
+ <p>
+ To apply the deltas, simply say:
+ <tscreen><verb>
+cd /where/ever/you/want/the/stuff
+ctm -v -v /where/you/store/your/deltas/src-cur.*
+ </verb></tscreen>
+ <p>
<tt/CTM/ understands deltas which have been put through <tt/gzip/,
so you do not need to gunzip them first, this saves disk space.
@@ -122,8 +124,8 @@
merely verify the integrity of the delta and see if it would apply
cleanly to your current tree.
- There are other options to <tt/CTM/ as well, look in the sources
- for more details.
+ There are other options to <tt/CTM/ as well, see the manual pages
+ or look in the sources for more information.
I would also be very happy if somebody could help with the ``user
interface'' portions, as I have realized that I cannot make up my
@@ -137,24 +139,69 @@
Even if you only have floppy disks, consider using <tt/fdwrite/ to
make a copy.
+ <sect2><heading>Keeping your local changes</heading>
+ <p>
+ As a developer one would like to experiment with and change
+ files in the source tree. CTM supports local modifications in a
+ limited way: before checking for the presence of a file
+ <tt>foo</tt>, it first looks for <tt>foo.ctm</tt>. If this
+ file exists, CTM will operate on it instead of <tt>foo</tt>.
+ <p>
+ This behaviour gives us a simple way to maintain local changes:
+ simply copy the files you plan to modify to the corresponding
+ file names with a <tt>.ctm</tt> suffix. Then you can freely hack
+ the code, while CTM keeps the <tt>.ctm</tt> file upto-date.
+
+ <sect2><heading>Other interesting CTM options</heading>
+ <sect3><heading>Finding out exactly what would be touched by an update</heading>
+ <p>
+ You can determine the list of changes that CTM will make on your
+ source repository using the ``<tt>-l</tt>'' option to CTM.
+ <p>
+ This is useful if you would like to keep logs of the changes,
+ pre- or post- process the modified files in any manner, or just
+ are feeling a tad paranoid :-).
+
+ <sect3><heading>Making backups before updating</heading>
+ <p>
+ Sometimes you may want to backup all the files that would be changed
+ by a CTM update.
+ <p>
+ Specifying the ``<tt>-B backup-file</tt>'' option causes
+ CTM to backup all files that would be touched by a given CTM
+ delta to <tt>backup-file</tt>.
- <sect2><heading>Future plans for <tt/CTM/</heading>
+ <sect3><heading>Restricting the files touched by an update</heading>
+ <p>
+ Sometimes you would be interested in restricting the scope of a
+ given CTM update, or may be interested in extracting just a few
+ files from a sequence of deltas.
+ <p>
+ You can control the list of files that CTM would operate on by
+ specifying filtering regular expressions using the
+ ``<tt>-e</tt>'' and ``<tt>-x</tt>'' options.
+ <p>
+ For example, to extract an upto-date copy of
+ <tt>lib/libc/Makefile</tt> from your collection of saved CTM deltas,
+ run the commands:
+ <tscreen><verb>
+cd /where/ever/you/want/to/extract/it/
+ctm -e '^lib/libc/Makefile' ~ctm/src-cur.*
+ </verb></tscreen>
+ <p>
+ For every file specified in a CTM delta, the ``<tt>-e</tt>'' and
+ ``<tt>-x</tt>'' options are applied in the order given on the
+ command line. The file is processed by CTM only if it is
+ marked as eligible after all the ``<tt>-e</tt>'' and
+ ``<tt>-x</tt>'' options are applied to it.
+
+ <sect2><heading>Future plans for <tt/CTM/</heading>
<p>
Tons of them:
<itemize>
<item>
- Make local modifications to the tree possible. One way to do
- it could be this:<p> When <tt/CTM/ wants to edit the file
- ``<tt>foo/bar.c</tt>'', it would first check for the existence
- of <tt>foo/bar.c#CTM</tt> If this file exists, the delta is
- applied to it instead. This way the <tt>foo/bar.c</tt> file
- can be edited to suit local needs.
- <item>
- Make a ``restore file(s)'' option to <tt/CTM/, something like:
- <verb>
- ctm -r src/sys/i386/wd.c /here/are/my/deltas/src-cur.*
- </verb>
- would restore <tt/wd.c/ to the current status from the files.
+ Use some kind of authentication into the CTM system, so as to
+ allow detection of spoofed CTM updates.
<item>
Clean up the options to <tt/CTM/, they became confusing and
counter intuitive.
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