Regular expression to stop at first match

ghz 1years ago ⋅ 8962 views

Question

My regex pattern looks something like

<xxxx location="file path/level1/level2" xxxx some="xxx">

I am only interested in the part in quotes assigned to location. Shouldn't it be as easy as below without the greedy switch?

/.*location="(.*)".*/

Does not seem to work.


Answer

You need to make your regular expression lazy/non-greedy, because by default, "(.*)" will match all of "file path/level1/level2" xxx some="xxx".

Instead you can make your dot-star non-greedy, which will make it match as few characters as possible:

/location="(.*?)"/

Adding a ? on a quantifier (?, * or +) makes it non-greedy.

Note: this is only available in regex engines which implement the Perl 5 extensions (Java, Ruby, Python, etc) but not in "traditional" regex engines (including Awk, sed, grep without -P, etc.).