Development notes: June 2011

Sorting in Perl

Custom sorting method:

@sorted = sort {
if ($a eq 'aardvark') { return 1; }
elsif ($b eq 'aardvark') { return -1; }
else { return $a cmp $b; }
} @words;

Remember to test for the special case for both $a and $b.

Thanks

Common admin tasks in phpBB 3

Change the author of a post:

Click on the post
Click on the "Moderator Control Panel" link in the top left
Click on the "Post details" link on the right-hand side (note: It might look like a triangle with a question mark in it)
Scroll down to the bottom of the post, and you will see a drop-down menu to change the poster.

Easiest way to find yesterday's date in Perl

my ($year, $month, $day) = (localtime(time + 7 * 24 * 60 * 60))[5,4,3];
$year += 1900;
$month++;

svn: Files skipped

Is subversion displaying a message that some files/directories were "skipped" ?
If you are using symlinks, try cd'ing into the directory, or using the full path instead.

Prevent spammers from harvesting your email address

When you write your email address on a web page, use @ instead of @, and . instead of the dot.

That way, most email harvesting programs won't recognise it.

Here's a method using Javascript that should stop 100% of email harvesting programs.

However, just using a web contact form would work best.

Find dodgy characters in a file

This will print any characters with values higher than 127, i.e. non-ascii characters that might look like ascii, but really be breaking your processor.

perl -lne'while (my ($c) = $_ =~ m{^(.)}) { print "$c = ".ord($c) if ord($c) > 127; $_ =~ s/^.// }' file_to_check.something

A quick, manual way to confirm some characters really are what you think they are:

cat file_to_check.something | od -bc

Require a parameter/variable in bash

FILE=$1
if [[ -z "$FILE" ]]; then echo "usage: script_name.sh [filename]"; exit 1; fi

# don't forget the quotes around "$FILE", they will be required if $FILE has a space in it, and always use double [[ ]]

Add a pause to a bash script

read -p "Press any key to start backup..."

thanks

gmail without ssl/https

http://mail.google.com/mail?ui=html

How to use single quotes in a Perl one-liner

perl -le'$q=chr(39); print "quote mark: $q" '
(linux)

How to add a custom PHP page to phpBB3

There is a tutorial explaining how to add a static HTML page, with phpBB header and footer.

This is how to add a dynamic PHP page in a similar way:

Go to ACP | General | Security settings, and set "Allow php in templates" to "Yes".
Follow the tutorial at: http://wiki.phpbb.com/Practical.Add_custom_page
In the template (e.g. about_us.html), replace where it says "Content in here" with

Perl: Fix DBI::db->disconnect invalidates 1 active statement handle

Add this subroutine to the module:

sub DESTROY {
    my ($self) = @_;
    # Finish off our statement handle, so we don't get warnings like:
    # DBI::db->disconnect invalidates 1 active statement handle
    my $sth = $self->{data_handle};
    if (blessed($sth) && $sth->can('finish')) {
        $sth->finish;
    }
}

Things lacking in Eclipse for Perl

Using EPIC

You can't fold code on 'if' blocks, or any arbitrary block (only on subs and perldocs).
Word wrap causes the line numbers to be wrong (a single wrapped line has more than one line number)
Syntax highlighting is not a perfect fit (perhaps this or these might help):

POD and heredoc are both marked as 'Comment2' and so can't be different colours
Even though there is a 'Markup' entry, it doesn't seem to be used for POD
The colour of dollar signs can't be changed (it's the same as the variable name in vim)
Neither variables nor special characters change colour within interpolated strings (as in vim)

How to change a shape type in Visio

Install the "Super Utilities and Tools" add-in from Paul Herber's Sandrila Ltd.

Use the 'Shape | Substitute' command.

Create Eclipse project with existing files

Have your workspace as the directory above the directory containing your files.
Create the project with a name that is the same as your files directory.

The problem is, if there are lots of (unrelated) files, Eclipse will take a long time to load up.

There are other options, i.e.:

Create a new folder
Click the 'Advanced' button
Link to an external folder

sshfs on linux

sshfs -o uid=1000 -o gid=1000 example.com:/workplace /workplace

Where 1000 is your user and group ID from /etc/passwd

That's it!

Make a layer transparent in GIMP

Create a blank layer, filled with white
Right-click on the layer and choose 'Add Layer Mask'
Select 'Grayscale copy of layer'
Fill or draw on the layer with any colour (e.g. shades of gray)

the darker black you go, the more transparent the layer will become

Development notes