Question

Hy everyone, I’m having trouble with properly nesting while loops to read from 2 arrays.
I have 2 files from which I read the content:

file1: item_list.txt
string1 \n
string2 \n
string3 \n
...

file2: item+info.txt
string3 \t info1 \t info2 \t info3
string1 \t info7 \t info1 \t info4
string5 \t info2 \t info3
string2 \t info2 \t info4 \t info1

(values are separated by new lines and tabs only, I added one space between characters here just to increase readability).

I read from files using fgetcsv() function, and each row from file is stored as an array into a variable $data. I created a while loop with condition (!feof($fp)) to read through the file until the last row. But I can’t quite properly nest the second loop.

What I want to do with this:
read the first string found in file1, go to file2 and try to find that string. If there’s a match, get the info data for that string (all of the data, or just one, doesn’t matter). If there’s no match, return message “no match”. In either case, once the second loop has done it’s thing, I need to read the second string in file1, and do the search in file2 again. Repeat this as long as there is something to read from the file1.

here are two versions of my code, they don’t work, and I can’t figure out why.

//opening the files
$fp = fopen("$DOCUMENT_ROOT/test/item_list.txt", "r"); #raw item list
$pf = fopen("$DOCUMENT_ROOT/test/item+info.txt", "r"); #item+info list

//read from first file
$line=0;
while (!feof($fp)){
    $line++;
    $data1 = fgetcsv($fp, "1000", "\n");
    $item1= $data1[0];
    echo "line: $line. item_list: ".$item1; //just to see on screen what's happening
    print_r($data1); //same here, just to see what's going on
    echo"<br />";

    //searching for string in file2
    $row=0;
    while (!feof($pf)){
        $row++;
        $data2 = fgetcsv($pf, "1000", "\t");
        $item2= $data2[0];
        echo "line: $row. item+info: ".$item2; //just checking things on screen
        print_r($data2); //here too
        echo "<br />";

        //conditioning
        //equal strings
        if ($string1== $string2)
            echo $data2[1]."<br />";
        break;
    }
}

fclose($fp);
fclose($pf);

this used to work as long as the items in item_list.txt and item+info.txt are oredered
exactly the same (string1\nstring2\string3 ->
string1\tinfo1\nstring2\tinfo2\nstring3\tinfo3 – but that’s never going to happen in my
case, it’s impossible to order the items like that)

I tried to do it with foreach() statement do itterate through arrays, but the result is something that I can’t make any sense out of.

while (!feof($fp)){
    $data1 = fgetcsv($fp);
    foreach ($data1 as $token1) {
        while (!feof($pf)) {
            $data2 = fgetcsv($pf);
            foreach ($data2 as $value) {
                explode ("\t", $value);
                if ($token1 == $value[0])
                    echo $value[1];
            } 
            break;
        } 
    }
}

Answer 1

This should do it:

$file1 = file($DOCUMENT_ROOT . '/test/item_list.txt');
$file2 = file($DOCUMENT_ROOT . '/test/item+info.txt');

foreach ($file1 as $line)
{
    $line = rtrim($line); // just in case ...
    if ($line === '') continue;

    foreach($file2 as $infoline)
    {
        $infoline = explode("\t", rtrim($infoline);
        if ($line === $infoline[0])
        {
            array_shift($infoline);
            echo $line . '<br /><br />' . implode('<br />', $infoline);
            // $results[$line] = $infoline; // uncomment this if you need the search results stored for later use
            break;
        }
    }
}