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diff --git a/usr.sbin/ctm/README b/usr.sbin/ctm/README deleted file mode 100644 index 94c779a..0000000 --- a/usr.sbin/ctm/README +++ /dev/null @@ -1,85 +0,0 @@ -# ---------------------------------------------------------------------------- -# "THE BEER-WARE LICENSE" (Revision 42): -# <phk@FreeBSD.org> wrote this file. As long as you retain this notice you -# can do whatever you want with this stuff. If we meet some day, and you think -# this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp -# ---------------------------------------------------------------------------- -# -# $FreeBSD$ -# - -What will I not find in this file ? ------------------------------------ -Instructions on how to obtain FreeBSD via CTM. -Contact <CTM@FreeBSD.org> for that. - -What is CTM ? -------------- -CTM was originally "CVS Through eMail", but has since changed scope to be -much more general. -CTM is now meant to be the definitive way to make and apply a delta between -two versions of a directory tree. -There are two parts to this, making the delta and applying it. These are two -entirely different things. CTM concentrates the computation-burden on the -generation of the deltas, as a delta very often is applied more times than -it is made. Second CTM tries to make the minimal size delta. - -Why not use diff/patch ? ------------------------- -Good question. Primarily because diff and patch doesn't do their job very -well. They don't deal with binary files (in this case files with '\0' or -'\0377' characters in them or files that doesn't end in '\n') which isn't -a big surprise: they were made to deal with text-files only. As a second -gripe, with patch you send the entire file to delete it. Not particular -efficient. - -So what does CTM do exactly ? ------------------------------ -CTM will produce a file, (a delta) containing the instructions and data needed -to take another copy of the tree from the old to the new status. CTM means to -do this in the exact sense, and therefore the delta contains MD5 checksums to -verify that the tree it is applied to is indeed in the state CTM expects. - -This means that if you have modified the tree locally, CTM might not be able -to upgrade your copy. - -How do I make a CTM-delta ? ---------------------------- - -Read the source, and be prepared to have 2 copies of the tree; One is -the reference ("From") tree, and the other is the delta ("To") tree. -The mkCTM script will create the CTM diff of the differences between -the reference tree and the delta tree. A lot of scratch space is -required, and your machine will work hard. - -How do I apply a CTM-delta ? ----------------------------- -You pass it to the 'ctm' command. You can pass a CTM-delta on stdin, or -you can give the filename as an argument. If you do the latter, you make -life a lot easier for your self, since the program can accept gzip'ed files -and since it will not have to make a temporary copy of your file. You can -specify multiple deltas at one time, they will be processed one at a time. - -The ctm command runs in a number of passes. It will process the entire -input file in each pass, before commencing with the next pass. - -Pass 1 will validate that the input file is OK. The syntax, the data and -the global MD5 checksum will be checked. If any of these fail, ctm will -never be able to do anything with the file, so it will simply reject it. - -Pass 2 will validate that the directory tree is in the state expected by -the CTM-delta. This is done by looking for files and directories which -should/should not exists and by checking the MD5 checksums of files. - -Pass 3 will actually apply the delta. - -Should I delete the delta when I have applied it ? --------------------------------------------------- -No. You might want to selectively reconstruct a file latter on. - -Why is CTM not being maintained? --------------------------------- -Because CVSUP has improved on the concept quite a bit, and is now -the method of choice. - -Poul-Henning |