dir_list($dir, $sort_order, $pattern)

Return a $sort_order sorted list of files matching regex $pattern in a directory.

Calls $sort_order, which can be one of:

        alpha - alphabetical
reverse_alpha - alphabetical, reversed
  high_to_low - numeric, high to low
  low_to_high - numeric, low to high

file_put_contents($file, $contents)

Write $contents string to $file path. Because:

https://secure.php.net/manual/en/function.file-put-contents.php

file_get_contents($file)

Get contents string of $file path. Because:

https://secure.php.net/manual/en/function.file-get-contents.php

get_date('key', 'other_key', ...)

Return current date values for the given key. Valid keys are sec, min, hour, mday (day of month), mon, year, wday (day of week), yday (day of year), and isdst (is daylight savings).

Remember that year is given in years after 1900.

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