extracting my $string

[deep]

Hello,

Is there a good function for extracting a whole string from a haystack? Example $string = '<img src="something.jpg">';

Haystack:

bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla hello hello hello hello hello hello hello hello hello hello hello hello hello hello hello hello hello hello hello hello <img src="something.jpg"> bla hello bla hello bla hello bla hello bla hello bla hello bla hello bla hello bla hello bla hello bla hello bla hello bla hello

Thanks!

[TheDefender]

[man]preg_match()[/man]

[deep]

Im not sure how preg_match() works...? how do i extract the string above from a bigger text? thanks!