use php, grep and regex to search and replace lines of code in file

Question

I have a php file that can read the contents of other files perfectly and return them as a string.

$contents = $file->read(); // return as string.

i need to be able to search and replace certain lines

lines that begin with $this->Session->setFlash and end with , true)); must be replaced with

lines that begin with $this->Session->setFlash and end with , true), 'default', array('class'=>'flash_failure'));

I have grep in my machine, if that helps.

finally after the contents is changed, i have a function that will write the contents back

$file->write($contents);

I know this helps to find the lines, but I have no idea how to replace.

^.*Session->setFlash.*, true\)\);$

Answer 1

You can try:

$contents = $file->read(); // return as string.

// change contents.
$contents = preg_replace('/^(\$this->Session->setFlash.*?), true\)\);$/',"$1, true), 'default', array('class'=>'flash_failure'));",$contents);

$file->write($contents);

Answer 2

the solution is thus:

$contents = preg_replace('/^(.*Session->setFlash.*, true\))\);$/m',
                                         "$1, 'default', array('class'=>'flash_failure'));", $contents);

the multiline modifier is key.