Web developers notes,programming tutorials.

This little code snipplet can save and reload arrays recursive into/from a file. You can use this if you want to add a guestbook to your page and there’s no MySql database left, for example.
<?php

function SaveArrayToFile($vFile, $vArray)
{
// Every array starts with chr(1)+”{”
fwrite($vFile, “{”);

// Go through the given array
reset($vArray);
// Start a loop. One could put the “next” command here, but if an
// entry was empty, “next” would return false.
while (true)
{
// Get the current “record” of the array
$Current = current($vArray);
// Get the current key. I use addshashes cause the key could
// contain , and this would be interprated as End-Of-Record
$MyKey = addslashes(strval(key($vArray)));

// Is it a sub-array?
if (is_array($Current)) {
// Save the key into the file

fwrite($vFile, $MyKey.”");
// Call me (the function) using the sub array
SaveArrayToFile($vFile,$Current);
// Write the record delemitter.
fwrite($vFile, “”);
} else {
// Save the record into the file
$Current = addslashes($Current);
fwrite($vFile,”$MyKey$Current”);
}

// Proceed to the next record. Skip Empty records
++$i;
while (!next($vArray))
{
if (++$i > count($vArray)) break;
}
if ($i > count($vArray)) break;
}

// Close current array
fwrite($vFile,”}”);
}

// Load an array
// Syntax: LoadArrayFromFile(Handle of a BINARY opened file);
function LoadArrayFromFile($vFile)
{
// Create empty array
$ForRet = array();

// Does the file contain an array?
$Wert = fread($vFile,2);
if ($Wert != “{”) return;

// Again, start a loop
while (true) {

// Does the array end here?
if (NextMatches($vFile,”}”)) {
// Read in the closer-string, otherwise the function would fail.
fread($vFile,2);
// Return the array
return $ForRet;
}

// Get the key name
$MyKey = “”;
while (true) {
$Zeichen = fread($vFile,1);
if ($Zeichen == “”)
break;
else
$MyKey .= $Zeichen;
}
// Remove slashes
$MyKey = stripslashes($MyKey);

// Is it a sub-array ?
if (NextMatches($vFile,”{”)) {
// It is a subarray ^^
$ForRet[$MyKey] = LoadArrayFromFile($vFile);
// Skip the delemitter
fread($vFile,1);
} else {
// Read the value
$MyVal = “”;
while (true) {
$Zeichen = fread($vFile,1);
if ($Zeichen == “”)
break;
else
$MyVal .= $Zeichen;
}
// Parse the value into the array
$MyVal = stripslashes($MyVal);
$ForRet[$MyKey] = $MyVal;
}

// Continue
}
}

// Check if $Text is @ cursor position in $vFile
// Syntax: NextMatches($vFile, $Text);
function NextMatches($vFile, $Text)
{
// Save the current position in the file
$PrevPos = ftell($vFile);

// How long is $Text ?
$Jump = strlen($Text);

// Check if the file is long enaugh
$stats = fstat($vFile);
if (ftell($vFile) + $Jump > $stats[7])
return false;

// Read out a string as long as $Text
$Erg = fread($vFile,$Jump);

// Continue to the previous position.
// I don’t use whence for compatibility with PHP < 4
fseek($vFile, $PrevPos);

return ($Erg == $Text);
}

/*

An example:

Create an recursive array and save it. Reload it again and give it out.

—————-
*/

$MyGuestbook = array();
$MyGuestbook[1][’Name’] = “Test 1″;
$MyGuestbook[1][’Test’][1][1] = “Test 1.2.1″;
$MyGuestbook[1][’Test’][2] = “Test 1.3″;
$MyGuestbook[2][’Name’] = “Test 4″;
$MyGuestbook[3][’Test’] = “Test 5″;
$MyGuestbook[4] = “”;

for ($i=0; $i<15; $i++)
$MyGuestbook[’Subarray’][’Verybig’][$i] = strval($i);

$Datei = fopen(”Test.txt”,”wb”);
SaveArrayToFile($Datei, $MyGuestbook);
fclose($Datei);

$Datei = fopen(”Test.txt”,”rb”);
$My = LoadArrayFromFile($Datei);

echo($My[1][’Name’].”<br>”);
echo($My[1][’Test’][1][1].”<br>”);
echo($My[1][’Test’][2].”<br>”);
echo($My[2][’Name’].”<br>”);
echo($My[3][’Test’].”<br>”);
echo(”6:: “.$My[’Subarray’][’Verybig’][6].”<br>”);
echo($MyGuestbook[4]==”" ? “The last value is chr(0)” : “Sorry, my fault”);

fclose($Datei);
unlink(”Test.txt”);

/*
———————

*/

?>

This entry was posted on Thursday, February 1st, 2007 at 4:54 pm and is filed under Beginners Php / Php Novices. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.