On 19-10-12 03:39 , David Wall wrote: > I regularly 'build' GnuCOBOL compiler from source code - however it is > supplied in 'tar' format. > I use 'tar' to unpack it and then I need to make changes to certain > files all the time. > > Is there any program in Mingw 6.3.0 that I can utilise to do these > patches for me. The "patch" and "diff" tools are designed for this. > I installed msys-patch and checked thru the documentation - but it > processes a 'diff' file and > that confused me no end. Maybe I'll have to investigate how to produce a > 'diff' file. Yes. This is the process: first, 1. Make a copy of all the original files from the "tar". 2. Edit the copy manually, applying the changes you need (which is what you have done so far for all "tar" versions, so you could use the last version of your edited files instead). 3. Run "diff" to compare the original file set with the manually edited file set. Store the resulting diff output as a "diff file". This file a record of the changes that you made manually; it identifies the files that were changed, the places in the files that were changed, and the change (old text => new text). When, later, you get a new "tar", you run "patch" on the new files using the "diff file" that you got from step 3 above. "Patch" then reapplies the same changes you did on the original "tar" file set and which were recorded in the "diff file". "Patch" tolerates a certain amount of evolution in the "tar" files from one version to the next, but if there is too much of that -- for example, if a function that you changed, as shown in the "diff" file, no longer exists in the new "tar" files or has been moved somewhere far away -- "patch" reports an error and then you have to consider what to do and perhaps edit something manually again. If you have to do that, you can then make, with "diff", a new "diff file" that reflects this evolution of the "tar" files, and the new "diff file" should work better when the next new "tar" arrives. > What I'd like to do is tell a patch program to: > > 1. Find this file 2. Find this text in the file 3. Replace found > text with new text. That is exactly what the patch+diff combination can do. HTH, Niklas Holsti
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