installed dokuwiki, added to navbar, updated news

1 files changed, 158 insertions, 0 deletions

diff --git a/wiki/inc/SafeFN.class.php b/wiki/inc/SafeFN.class.php
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+<?php
+
+/**
+ * Class to safely store UTF-8 in a Filename
+ *
+ * Encodes a utf8 string using only the following characters 0-9a-z_.-%
+ * characters 0-9a-z in the original string are preserved, "plain".
+ * all other characters are represented in a substring that starts
+ * with '%' are "converted".
+ * The transition from converted substrings to plain characters is
+ * marked with a '.'
+ *
+ * @author   Christopher Smith <chris@jalakai.co.uk>
+ * @date     2010-04-02
+ */
+class SafeFN {
+
+    // 'safe' characters are a superset of $plain, $pre_indicator and $post_indicator
+    private static $plain = '-./[_0123456789abcdefghijklmnopqrstuvwxyz'; // these characters aren't converted
+    private static $pre_indicator = '%';
+    private static $post_indicator = ']';
+
+    /**
+     * Convert an UTF-8 string to a safe ASCII String
+     *
+     *  conversion process
+     *    - if codepoint is a plain or post_indicator character,
+     *      - if previous character was "converted", append post_indicator to output, clear "converted" flag
+     *      - append ascii byte for character to output
+     *      (continue to next character)
+     *
+     *    - if codepoint is a pre_indicator character,
+     *      - append ascii byte for character to output, set "converted" flag
+     *      (continue to next character)
+     *
+     *    (all remaining characters)
+     *    - reduce codepoint value for non-printable ASCII characters (0x00 - 0x1f).  Space becomes our zero.
+     *    - convert reduced value to base36 (0-9a-z)
+     *    - append $pre_indicator characater followed by base36 string to output, set converted flag
+     *    (continue to next character)
+     *
+     * @param    string    $filename     a utf8 string, should only include printable characters - not 0x00-0x1f
+     * @return   string    an encoded representation of $filename using only 'safe' ASCII characters
+     *
+     * @author   Christopher Smith <chris@jalakai.co.uk>
+     */
+    public static function encode($filename) {
+        return self::unicode_to_safe(utf8_to_unicode($filename));
+    }
+
+    /**
+     *  decoding process
+     *    - split the string into substrings at any occurrence of pre or post indicator characters
+     *    - check the first character of the substring
+     *      - if its not a pre_indicator character
+     *        - if previous character was converted, skip over post_indicator character
+     *        - copy codepoint values of remaining characters to the output array
+     *        - clear any converted flag
+     *      (continue to next substring)
+     *
+     *     _ else (its a pre_indicator character)
+     *       - if string length is 1, copy the post_indicator character to the output array
+     *       (continue to next substring)
+     *
+     *       - else (string length > 1)
+     *         - skip the pre-indicator character and convert remaining string from base36 to base10
+     *         - increase codepoint value for non-printable ASCII characters (add 0x20)
+     *         - append codepoint to output array
+     *       (continue to next substring)
+     *
+     * @param    string    $filename     a 'safe' encoded ASCII string,
+     * @return   string    decoded utf8 representation of $filename
+     *
+     * @author   Christopher Smith <chris@jalakai.co.uk>
+     */
+    public static function decode($filename) {
+        return unicode_to_utf8(self::safe_to_unicode(strtolower($filename)));
+    }
+
+    public static function validate_printable_utf8($printable_utf8) {
+        return !preg_match('#[\x01-\x1f]#',$printable_utf8);
+    }
+
+    public static function validate_safe($safe) {
+        return !preg_match('#[^'.self::$plain.self::$post_indicator.self::$pre_indicator.']#',$safe);
+    }
+
+    /**
+     * convert an array of unicode codepoints into 'safe_filename' format
+     *
+     * @param    array  int    $unicode    an array of unicode codepoints
+     * @return   string        the unicode represented in 'safe_filename' format
+     *
+     * @author   Christopher Smith <chris@jalakai.co.uk>
+     */
+    private static function unicode_to_safe($unicode) {
+
+        $safe = '';
+        $converted = false;
+
+        foreach ($unicode as $codepoint) {
+            if ($codepoint < 127 && (strpos(self::$plain.self::$post_indicator,chr($codepoint))!==false)) {
+                if ($converted) {
+                    $safe .= self::$post_indicator;
+                    $converted = false;
+                }
+                $safe .= chr($codepoint);
+
+            } else if ($codepoint == ord(self::$pre_indicator)) {
+                $safe .= self::$pre_indicator;
+                $converted = true;
+            } else {
+                $safe .= self::$pre_indicator.base_convert((string)($codepoint-32),10,36);
+                $converted = true;
+            }
+        }
+        if($converted) $safe .= self::$post_indicator;
+        return $safe;
+    }
+
+    /**
+     * convert a 'safe_filename' string into an array of unicode codepoints
+     *
+     * @param   string         $safe     a filename in 'safe_filename' format
+     * @return  array   int    an array of unicode codepoints
+     *
+     * @author   Christopher Smith <chris@jalakai.co.uk>
+     */
+    private static function safe_to_unicode($safe) {
+
+        $unicode = array();
+        $split = preg_split('#(?=['.self::$post_indicator.self::$pre_indicator.'])#',$safe,-1,PREG_SPLIT_NO_EMPTY);
+
+        $converted = false;
+        foreach ($split as $sub) {
+            $len = strlen($sub);
+            if ($sub[0] != self::$pre_indicator) {
+                // plain (unconverted) characters, optionally starting with a post_indicator
+                // set initial value to skip any post_indicator
+                for ($i=($converted?1:0); $i < $len; $i++) {
+                    $unicode[] = ord($sub[$i]);
+                }
+                $converted = false;
+            } else if ($len==1) {
+                // a pre_indicator character in the real data
+                $unicode[] = ord($sub);
+                $converted = true;
+            } else {
+                // a single codepoint in base36, adjusted for initial 32 non-printable chars
+                $unicode[] = 32 + (int)base_convert(substr($sub,1),36,10);
+                $converted = true;
+            }
+        }
+
+        return $unicode;
+    }
+
+}