Question

Having lines

(01) Some text
(10) Foo Bar
(11) ?
(13) Foo Bar
(13) ?
(20) Something else

check 4 rows in a batch. If row 1 and 3 are the same and row 2 and 4 are (XX) ?, then replace rows 2-4 with ... so it results as

(01) Some text
(10) Foo Bar
...
(20) Something else

---

Code:

$arr = explode("\n", $t);
if ( count($arr) > 3 )  {
    for ($i=1; $i<count($arr); $i++) { // check 4 rows
        if( ($arr[$i-1] == $arr[$i+1]) // if row 1 and 3 are the same
           && preg_match('/\(\d+\) \?$/', $arr[$i]) // and row 2 is "(XX) ?"
        && preg_match('/\(\d+\) \?$/', $arr[$i+2])  // and row 4 is "(XX) ?"
       ) {
            print "Match!"; //test. later replace rows 2-4 with a row "..."
         }
     }
}

This currently gives me an offset error.

Test: http://codepad.viper-7.com/iMO3BW

How could this be solved?

Answer 1

Use regex pattern

^(\(\d+\)\s+)(.*)[\n\r]\(\d+\)\s+\?[\n\r]\(\d+\)\s+\2[\n\r]\(\d+\)\s+\?[\n\r]

with multiline and global modifiers.

---

See this regex test.