preg_match_all对字符串中的进程ID

Question

I'm trying to get certain ids from a string, but I can't get it to work. I'm getting values that I'm not expecting in my result.

This is what I have:

<?php
$grep = ' 7027 ?        S      0:00 nginx: worker process                                          
 7632 ?        S      0:00 sh -c ps ax | grep nginx
 7634 ?        S      0:00 grep nginx
16117 ?        Ss     0:00 nginx: master process /usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf';


if ( preg_match_all('~([0-9]+) \?(.*?)nginx:~si', $grep, $matches) )
{   
    echo '<pre>';
    print_r($matches);
    echo '</pre>';
}

What I'm expecting here with: ~([0-9]+) \?(.*?)nginx: is that it would match these two lines:

7027 ?        S      0:00 nginx: worker process  
16117 ?        Ss     0:00 nginx: master process /usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf';

I'm specifically after their process id, in this case: 7027 and 16117.

But I'm getting: 7027 and 7632 instead.

How should my regex look to get the data that I want?

Here's a demo: http://codepad.viper-7.com/2R5OfF

Answer 1

The s modifier forces the . to match across newline sequences. You need to remove it and then you can simplify your regular expression as follows to return the process id's you're after.

preg_match_all('~(\d+).*nginx:~i', $grep, $matches);
print_r($matches[1]);

Output

Array
(
    [0] => 7027
    [1] => 16117
)