search for the content of textarea1 in textarea2 - php

Question

how i can search for the content of textarea1 in textarea2 and print the whole line matches
example:
textarea1 contents(words)
content1
content2
content3
textarea2 contents(the lines)
this is content1
this is cont
this content3
so i want the printed matches lines like this
this is content1
this content 3
because content1 and content 3 in my textarea1

Answer 1

Here comes an example using preg_match(), note that the search strings have to be quoted by preg_quote():
$text1 = $_POST['text_area1'];
$text2 = $_POST['text_area2'];
// split search texts. in this case we use new line
$search = explode("\n", preg_quote($text1));
// now prepare for a regex
$regex = '~(' . implode('|', $search) . ')~';
// now split the text by newline
$lines = explode("\n", $text2);
foreach($lines as $line) {
if(preg_match($regex, $line)) {
print $line . "\n";
}
}
Output:
this is content1
this content3
Note that you may refine the way how you separate the search strings. In my example I split them by newline, but you may wish them additionally splitted by spaces or , ...

Answer 2

$textarea1 = "content1\ncontent2\ncontent3";
$chunks = explode("\n", $textarea1);
$textarea2 = "this is content1\nthis is cont\nthis is content3";
$lines = explode("\n", $textarea2);
foreach ($chunks as $c)
foreach ($lines as $l)
if (strpos($l, $c))
echo $l . '<br>';

Answer 3

To use regex in this case is a bit too much in my opinion, just use basic string-functions offered by php:
// the \n is the line break smybol used in the textarea
$needle = "content1\ncontent2\ncontent3"; // this text is probably received via $_GET['text1'] or something similar
$haystack = "this is content1\nthis is cont\nthis is content3";
// get all lines
$needle_lines = explode("\n", $needle);
$haystack_lines = explode("\n", $haystack);
foreach($haystack_lines as $hline) {
foreach ($needle_lines as $line) {
if (strpos($hline, $line) === false)
continue;
echo $hline."<br />";
//continue the outer foreach since we already found a match for the haystack_line
continue 2;
}
}
Update #1:
This code iterates through all lines in your haystack and checks for every needle in it.
If it finds one needle the line is printed via echo and we proceed with the next line of the haystack - is there anything more needed?