How to change the colours of directories and files

To change the colour of directories from dark blue to light blue (cyan):

    export LS_COLORS=$(echo $LS_COLORS|sed 's/di=01;34/di=01;36/')

See also

    man dircolors

and

    dircolors --print-database

...for a list of the colours.

System maintenance

There is a reason we have a process of change control. It has become a dirty word in some departments, but the bare minimum is:

• making a change in the development environment
• testing it, preferably by more than one person/team
• packaging up the release and labeling it properly
• making a formal request to deploy it, including roll-back instructions

In addition, a precedent should never be set to fix something that another department has broken!

Log4perl

    use Log::Log4perl qw(:easy);
    Log::Log4perl->easy_init($ERROR); 

    DEBUG "This doesn't go anywhere";
    ERROR "This gets logged";

See stored procedures in MySQL

List them

mysql> show procedure status;

See the code of one

mysql> show create procedure [name];

Perl sprintf

        # Format number with up to 8 leading zeroes
        $result = sprintf("%08d", $number);

        # Round number to 3 digits after decimal point
        $rounded = sprintf("%.3f", $number);

Perl's sprintf permits the following universally-known conversions:

   %% a percent sign
 %c a character with the given number
 %s a string
 %d a signed integer, in decimal
 %u an unsigned integer, in decimal
 %o an unsigned integer, in octal
 %x an unsigned integer, in hexadecimal
 %e a floating-point number, in scientific notation
 %f a floating-point number, in fixed decimal notation
 %g a floating-point number, in %e or %f notation