Linux – diff folders and copy results over

centoscopydiff()fileslinux

We use a third party newsletter system which updates frequently, usually around 100 files. Each time all the developers release is the whole application again with a changelog but there's usually too many files listed for it to be useful. The system – once online – generates a lot of files (caches etc) so i dont want to download the remote files to do a local diff each time either. What i want to do is upload the zip of all the newly released files and run a Diff (or similar) and copy over from new_files -> existing_files just the updated files and ignore the files in existing that aren't in new. Whats the best way to do this?

I know this can be achieved to an extent using copy but its my understanding that this is largely based on last edited date but i'm more interested in actual file differences

This is on CentOS 5 and i have shell access

Thanks.

Best Answer

With linux, ssh in and use rsync

this will help

http://troy.jdmz.net/rsync/index.html

Try comm

Another way to look at it:

Show lines that only exist in file a: (i.e. what was deleted from a)
```
  comm -23 a b
```
Show lines that only exist in file b: (i.e. what was added to b)
```
  comm -13 a b
```
Show lines that only exist in one file or the other: (but not both)
```
  comm -3 a b | sed 's/^\t//'
```

(Warning: If file a has lines that start with TAB, it (the first TAB) will be removed from the output.)

Sorted files only

NOTE: Both files need to be sorted for comm to work properly. If they aren't already sorted, you should sort them:

sort <a >a.sorted
sort <b >b.sorted
comm -12 a.sorted b.sorted

If the files are extremely long, this may be quite a burden as it requires an extra copy and therefore twice as much disk space.

Best Answer

Related Solutions

SSH – How to Perform Diff Over SSH

How to get diff to show only added and deleted lines? If diff can’t do it, what tool can

Try comm

Sorted files only

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