I have a string [from a file]:
ILX [New for 2013!]
Overview: The least expensive route to Honda's premium-label goodness
Drivetrain: Two four-cylinder engines to choose from as well as a gas-electric hybrid; front-wheel-drive only.
How I get the string:
$writeup = file_get_contents[$car_files_path . $manufacture . '/Stories/'.$story];
I want to match the overview line [Overview: The least expensive route to Honda's premium-label goodness]. What is the best way to achieve this.
I tried .*\n, but that will match everything and then a new line. Is there a way to make regex non-greedy?
I have tried: preg_match['/^Overview:\s.*$/im', $writeup, $overall_matches] and I don't get any matches
asked Feb 19, 2013 at 21:10
Chris MuenchChris Muench
17.9k69 gold badges204 silver badges352 bronze badges
3
Add ? after the quantifier to make it ungreedy. In this case, your regex would be .*?\n.
To specifically match the line beginning with "Overview: ", use this regex:
/^Overview:\s.*$/im
The m modifier allows ^ and $ to match the start and end of lines instead of the entire search string. Note that there is no need to make it ungreedy since . does not match newlines unless you use the
s modifier - in fact, making it ungreedy here would be bad for performance.
answered Feb 19, 2013 at 21:13
9
Summary: in this tutorial, you’ll learn about the regex non-greedy [or lazy] quantifiers that match their preceding elements as few times as possible.
Introduction to the regex non-greedy [or lazy] quantifiers
In regular expressions, the quantifiers have two versions: greedy and non-greedy [or lazy]. In the previous tutorial, you learned how greedy quantifiers work.
To turn a greedy quantifier into a non-greedy quantifier, you can append a question mark [?] to it. The following table shows the greedy and non-greedy quantifiers:
*
| *?
| Match its preceding element zero or more times. |
+
| +?
| Match its preceding element one or more times. |
?
| ??
| Match its preceding element zero or one time. |
{ n }
| { n }?
| Match its preceding element exactly n times. |
{ n ,}
| { n ,}?
| Match its preceding element at least n times. |
{ n , m }
| { n , m }?
| Match its preceding element from n to m times. |
The following example uses the non-greedy quantifier [+?] to match the text within the quotes [""]: