How to check if line exists in a file

Question

I want to check if a line exists in a file so that I avoid the same line repetition. I have put a dev restriction to the site to only allow myself to view it, others are redirected to "unavailable.php" page
But I want to allow people to view site if they request a permission
In my case, I have a .htaccess file

Options +FollowSymlinks
RewriteEngine On
RewriteCond %{REMOTE_HOST} !^34\.120\.121\.20 #this a random ip
RewriteCond %{REQUEST_URI} !path/to/first/exception\.php$ #first exception is 'unavailable.php'
RewriteCond %{REQUEST_URI} !path/to/another/exception\.php$ #the second exception is 'request_permission.php'
RewriteRule \.php$ /redirect/to/first/exception/ [L]

and in request_permission.php, I have the following code:

<?php
    $ip = $_SERVER['REMOTE_ADDR'];
    $data = file('.htaccess');
    $parts = explode(' ', $data[2]);
    $parts_end = end($parts);
    $parts_substred = substr($parts_end, 2); 
    $ip_addr = str_replace('\\', '', $parts_substred); 
    if ($ip_addr != $ip){
        $new_ip = str_replace('.', '\\.', $_SERVER['REMOTE_ADDR']);
        $new_string = str_replace($parts_end, "", $data[2]) . "!^".$new_ip;
        $string = $data[0].$data[1].$data[2].$new_string.PHP_EOL.$data[3].$data[4].$data[5];
        //file_put_contents(".htaccess", $string);
    }
?>

Now everytime I visit request_permission.php a new line, like this is being created: RewriteCond %{REMOTE_HOST} !^56\.80\.1\.15 (let's say this is my ip).

I want to check if the line with my IP address exists in htaccess, do that I won't duplicate it again.

I tried to use strpos() but it doesn't find my IP address even if that exists.

How should I do this?

Something like this? http://stackoverflow.com/questions/19760564/php-find-a-string-in-file-then-show-its-line-number — bloodyKnuckles, Mar 15 '15 at 14:25
You use the wrong approach. Do not modify an `.htaccess` style file for this. Instead take a look at the documentation: there are means to access a database in background for this. Much more convenient, less error prone, easier. — arkascha, Mar 15 '15 at 14:25
humm, then how can I allow that IP if I don't modify the `.htaccess` file? — Cristian Alexandru, Mar 15 '15 at 14:29
In your code you are explicitly requiring that duplicate to be in the 3rd line (`$data[2]`) and if it exists somewhere else then you ignore it (thus perhaps duplicating it). Can I assume this is NOT what you are wanting to do? — Peter Bowers, Mar 15 '15 at 14:32
Christian, I recommend you to not use .htaccess for this. Another approach, is rely on a database, where you may persist the IP data of the authorized person. (to check this, you just may create an include file that will check the remote address (in $_SERVER) and match against the data in your database. If there`s no match, means it has no access to that place. — Thiago Elias, Mar 15 '15 at 14:34
Was this question a reply to my comment? "then how can I allow that IP if I don't modify the .htaccess file?" Well, didn't I say so? " — arkascha, Mar 15 '15 at 14:35
@ThiagoElias `.htaccess` style file is perfectly fine, if you combine it with a database. :-) — arkascha, Mar 15 '15 at 14:36
@arkascha: yes, it was | I use it together with a database in the real project, to track the expiration time.. in fact I only allow permission for 7 hours/day — Cristian Alexandru, Mar 15 '15 at 14:38
I agree with you @arkascha =D (my concern is just about rely only in .htaccess) bigger .htaccess file will result in performance loss.. I had to deal with some awful .htaccess file in my old job haha.. I don't even like to remember.. They looked like an horror movie.. hahah — Thiago Elias, Mar 15 '15 at 14:39
@ThiagoElias OK, I just mentioned that because in your comment above you suggest a php based database access which is something totally different. — arkascha, Mar 15 '15 at 14:40

Peter Bowers · Accepted Answer · 2015-03-15T15:37:20.127

2

I would just look for any REMOTE_HOST line using a regex in preg_match() and then append the needed line if it's not found:

Do note that I fully agree with the opinions of others that this is not really a GOOD solution. I am answering the question but recommending at the same time that you look for some alternate way...

My original (now deleted) had some problems - this one works, albeit still doing something I don't think you should do (I'm just copying in the whole test script for ease - you'll need to go back to reading the file):

<?php

$ip = '34.120.121.29';
$ip_pat = str_replace('.', '\\\\\\.', $ip);
# Note that I'm using $data as a straight string, not an array - use file_get_contents() to read it
$data = <<<EOF
Options +FollowSymlinks
RewriteEngine On
RewriteCond %{REMOTE_HOST} !^34\.120\.121\.20 #this a random ip
RewriteCond %{REQUEST_URI} !path/to/first/exception\.php$ #first exception is 'unavailable.php'
RewriteCond %{REQUEST_URI} !path/to/another/exception\.php$ #the second exception is 'request_permission.php'
RewriteRule \.php$ /redirect/to/first/exception/ [L]
EOF;
$pat = '^RewriteCond *%{REMOTE_HOST} *';
if (!preg_match("/$pat.*$ip_pat/m", $data)) {
    #echo "NO MATCH<br />\n";
    $new_ip = str_replace('.', '\\.', $ip);
    $new_string = preg_replace("/$pat/m", "RewriteCond %{REMOTE_HOST} !^$new_ip".PHP_EOL."$0", $data);
    #$data .= $new_string.PHP_EOL;
    echo nl2br("$new_string");
}

Note the use of the limit parameter in the call to preg_replace() to only replace the first occurrence. If you don't do that then your 3rd addition will be doubled and your 4th addition will be quadrupled and so on.

edited Mar 15 '15 at 15:37

answered Mar 15 '15 at 14:41

Peter Bowers

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@arkascha, please re-read my evaluative paragraph. I said I agree with others that it is *not* (emphasis added) a good idea and that the OP look for some *alternate* way. – Peter Bowers Mar 15 '15 at 15:01
the snippet gives me an error, that `preg match requests at least 2 parameters, 1 given`, where did you search that: `/RewriteCond *%\{REMOTE_HOST\} *!^'.$ip_pat.'/'`? – Cristian Alexandru Mar 15 '15 at 15:04
Look at the part below where I edited it. Adding the extra argument into the preg_match was just one needed change... – Peter Bowers Mar 15 '15 at 15:05
It doesn't do what I expect to. Here is the rendered result: `NO MATCH | Options +FollowSymlinks | RewriteEngine On | RewriteCond %{REMOTE_HOST} !^34\.120\.121\.29 !^34\.120\.121\.20 #this a random ip | RewriteCond %{REQUEST_URI} !path/to/first/exception\.php$ #first exception is 'unavailable.php' | RewriteCond %{REQUEST_URI} !path/to/another/exception\.php$ #the second exception is 'request_permission.php' | RewriteRule \.php$ /redirect/to/first/exception/ [L]` – Cristian Alexandru Mar 15 '15 at 15:16
Since it's a comment I'm not sure if the issue is newlines or if you don't like the placement of the new IP address. Please be specific about what you are expecting. – Peter Bowers Mar 15 '15 at 15:21
The problem is here: `RewriteCond %{REMOTE_HOST} !^34\.120\.121\.29 !^34\.120\.121\.20`, notice there are 2 IPs separated by a space, what I need is that each IP to be on a new line, with `RewriteCond %{REMOTE_HOST}` before the second one as well. – Cristian Alexandru Mar 15 '15 at 15:25
Looks from this link http://stackoverflow.com/questions/8602399/allow-multiple-ips-to-access-wordpress-site-admin-via-htaccess that your proposed solution isn't going to work. You will need to put all the IPs on the same line, but in a slightly different syntax. – Peter Bowers Mar 15 '15 at 15:50
Your last edited answer has been accepted, as it did what I wanted! Thank you so much – Cristian Alexandru Mar 15 '15 at 16:54
The `m` pattern modifier has no impact on the pattern because the pattern does not contain any starting or ending anchors in it (`^` or `$`). – mickmackusa Jan 16 '23 at 00:58

How to check if line exists in a file

1 Answers1