KCachegrind doesn’t open cachegrind profiler log file

So I had an issue with KCachegrind where I would open a cachegrind profile file and "nothing happened". The status bar said the file had loaded, but the user interface widgets were all empty. Turns out clicking Settings -> Sidebars -> Function Profile loaded the part of the UI I needed to get started... everything is easy when you know how!

Apache2 REQUEST_FILENAME requires DOCUMENT_ROOT

I had a problem with my rewrite rules, that looked like this:

  DocumentRoot /var/www/trust.jj5.net
  RewriteEngine On
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteRule (.*) http://trust.jj5.net/sorry.html [L,R]

I was trying to redirect any request which didn't match a file or directory. The !-f and !-d requirements were failing because the path to the REQUEST_FILENAME wasn't fully qualified. I fixed the problem by including the DOCUMENT_ROOT:

  DocumentRoot /var/www/trust.jj5.net
  RewriteEngine On
  RewriteCond %{DOCUMENT_ROOT}%{REQUEST_FILENAME} !-f
  RewriteCond %{DOCUMENT_ROOT}%{REQUEST_FILENAME} !-d
  RewriteRule (.*) http://trust.jj5.net/sorry.html [L,R]

Happy days! :)

Making directories executable and files read and writeable

I had a problem with my rsync backups. The problem was that the first time I ran it everything worked fine. The second time it ran (and all subsequent times) I got back the phone book of error messages, because the first time I'd run rsync it had copied in a whole heap of read-only files, and then when I ran it again it wasn't able to overwrite those read-only files. At least I think that was what was happening. So I added the following to my backup script:

  find . -type d -exec chmod u+x {} \;
  if [ "$?" -ne "0" ]; then
    echo "Cannot chmod directories in '$PWD'.";
    exit 1;
  fi
  find . -type f -exec chmod u+rw {} \;
  if [ "$?" -ne "0" ]; then
    echo "Cannot chmod files in '$PWD'.";
    exit 1;
  fi

This code runs after rsync and processes the files and directories that have been synchronised. That is, it processes the copy of the data, not the data I copied from.

For the copy of the data I want to make sure that the owner of the files can read and write them and that the owner of the directories can execute them. So that's what the above code does.