preg_replace issue

Question

I would like to put a text instead of the string VERSION=20101203, my problem is only the first field of preg_replace, I am new to regular expresions. I don't know exactly how to tell preg_replace to see that I need to change the string VERSION=20101203 for other text.

So the string has the format: VERSION=YEARMONTHDAY

I was trying with:

$new_content = preg_replace('/^VERSION\=[0-9]{8}/', $replacement, $content);

Where:

$replacement is the new string I want to have $content is the content of a file that it doesn't matter here

I beleive it's not too difficult. Any questions you may have with this issue please ask me and I will answer quickly

Thank you very much in advance

Answer 1

^ is anchoring the regular expression to only the beginning of the line. I assume that's part of the problem.

$new_content = preg_replace('/VERSION\=[0-9]{8}/', $replacement, $content);

In addition, you will want to ensure that $replacement contains the full string for replacing the string matched by VERSION\\=[0-9]{8} .

Answer 2

Try this code (without ^ at the start of regular expression):

$content='foo VERSION=20101203 foo bar';
var_dump( preg_replace('/VERSION=[0-9]{8}/', 'replacement', $content));

OUTPUT

string(23) "foo replacement foo bar"

Answer 3

Well it was solved with Jason McCreary's suggestion. It worked just without ^ and the rest of the code is the same as I had it before.

I was trying to change the string VERSION=YEARMONTHDAY (which is in one of the lines of the $ks file). I mean that the file contains in one of its lines this: VERSION=20101203 (or any other date, but everytime with the same format)

That string is going to be changed by a new one that matches to the last modification of the file stored in the variable $ks. ($ks is the name of the file)

    $last_modification = filemtime($ks);
    $last_modification = date("Ymd", $last_modification);

    // $last_modification (for instance suppose it is VERSION=20110622)
    $last_modification="VERSION=" . $last_modification;

    // Open the file in order to change the string
    $file = $ks;
    $fh = fopen($ks, 'r+');
    $content = fread($fh, filesize($ks));

    $new_content = preg_replace('/VERSION\=[0-9]{8}/', $last_modification, $content);
    fclose($fh);

    // Open the file in order to write inside it
    $fh = fopen($ks, 'r+');
    fwrite($fh, $new_content);
    fclose($fh); 

So the final result is going to be: the file named $ks will have a line with VERSION=20110622 instead of the VERSION=20101203 (or any other older date) string.

The code is working fine this way for me. Thank you all again, I don't know if I have to close this issue, as it is solved

PD: Sorry for my english