-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Tue, Apr 27, 2004 at 09:38:04AM -0700, Debee Norling wrote: > Well the more I read, it seems the less I know. Debee, Maybe the thing to do is to master the new territory one neighborhood at a time. Here is my understanding of a "patch": There are two related utilities in Linux called "diff" and "patch". They are closely related and are inverse functions of each other. Suppose you have a source program called oldprog.c and you improve it, turning it into another source program called newprog.c. When you want to share your changes with the original author, you do not send him your newprog.c. Instead you run the "diff" utility something like this: prompt # diff oldprog.c newprog.c > differences The file "differences" is interesting. It tells how newprog.c gets to be created from oldprog.c, and it is just what the original author wants. The file "differences" is called a "patch". The "patch" utility applies the patch created earlier and stored in the file "differences" to "oldprog.c", and you then have yourself a "newprog.c" which you can compile and do whatever you want with. A kernel patch is a "differences" file which you apply to a set of kernel source programs (a source "tree") so the standard kernel now becomes a new, nonstandard, modified, hopefully improved, kernel. You then compile it, install it, run "lilo", and hold your breath. You can obtain patches that upgrade a kernel from one version to the next. For instance, kernel 2.4.25, which I am using, could be upgraded to 2.4.26 by obtaining and applying the proper patch with the "patch" utility. I could upgrade from 2.4.20 all the way to 2.4.26 also, but it would have to be incrementally, without skipping any of the middle steps. Speakup is not a program in the usual sense. It is a kernel patch. It is a set of modifications to a standard kernel, which when applied with the patch utility, give you a "speakup modified kernel" that needs to be compiled, installed, etc. Diff creates a patch by extracting the differences between two source files. Patch applies those differences to produce the new version from the old one. Quiz next class. Chuck - -- The Moon is Waxing Gibbous (52% of Full) My home page is now at http://www.mhcable.com/~chuckh -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iQCVAwUBQI7i6jVdG8M9x9tGAQJkvAQA0dBn2dYo7bVKKJcLVd4NpeJj+g+akvug iEkMIW2+MbAh7pNl2kkhW0f3+8LkGBCkRLdVEIOE99YZCb+6UU9TeJAfJ7vlwvGu TsUuKbKKpq9CbKrx4BfqFiFdgCA61eI3kgPbMnZsCZo53TcrJvBd1EVx0pFtcMoO 663h1wpR41M= =sCBD -----END PGP SIGNATURE-----
