non-greedy

问题 How come my regex pattern isn't lazy? It should be capturing the first number, not the second. Here is a working bash script.. #!/bin/bash text='here is some example text I want to match word1 and this number 3.01 GiB here is some extra text and another number 1.89 GiB' regex='(word1|word2).*?number[[:blank:]]([0-9.]+) GiB' if [[ "$text" =~ $regex ]]; then echo 'FULL MATCH: '"${BASH_REMATCH[0]}" echo 'NUMBER CAPTURE: '"${BASH_REMATCH[2]}" fi Here is the output... FULL MATCH: word1 and this

问题 How come my regex pattern isn't lazy? It should be capturing the first number, not the second. Here is a working bash script.. #!/bin/bash text='here is some example text I want to match word1 and this number 3.01 GiB here is some extra text and another number 1.89 GiB' regex='(word1|word2).*?number[[:blank:]]([0-9.]+) GiB' if [[ "$text" =~ $regex ]]; then echo 'FULL MATCH: '"${BASH_REMATCH[0]}" echo 'NUMBER CAPTURE: '"${BASH_REMATCH[2]}" fi Here is the output... FULL MATCH: word1 and this

问题 I have a very simple regex similar to this: HOHO.*?_HO_ With this test string... fiwgu_HOHO_HOHO_HOHOrgh_HOHO_feh_HOHO___HO_fbguyev I expect it to match just _HOHO___HO_ (shortest match, non-greedy) Instead it matches _HOHO_HOHO_HOHOrgh_HOHO_feh_HOHO___HO_ (longest match, looks greedy). Why? How can I make it match the shortest match? Adding and removing the ? gives the same result. Edit - better test string that shows why [^HOHO] doesn't work: fiwgu_HOHO_HOHO_HOHOrgh_HOHO_feh_HOHO_H_O_H_O_HO

问题 I using regex search to replace the following string: \new{}\new{\textbf{test1}}\new{test2} with \textbf{test1}test2 I used regex replace with \new{(.*)} to find and \1 to replace. however the search always match the whole line of my original string and the replace reuslt is: }\new{\textbf{test1}}\new{test2 far from what I need. In regex expression in Java, you can use a ? after a quantifier makes it a reluctant quantifier. It then tries to find the smallest match. So in java, my search regex

问题 I am having a problem with a non-greedy regular expression. I've seen that there are questions regarding non-greedy regex, but they don't answer to my problem. Problem: I am trying to match the href of the "lol" anchor. Note: I know this can be done with perl HTML parsing modules, and my question is not about parsing HTML in perl. My question is about the regular expression itself and the HTML is just an example. Test case: I have 4 tests for .*? and [^"] . The 2 first produce the expected

问题 I need to match @anything_here@ from a string @anything_here@dhhhd@shdjhjs@ . So I'd used following regex. ^@.*?@ or ^@[^@]*@ Both way it's work but I would like to know which one would be a better solution. Regex with non-greedy repetition or regex with negated character class? 回答1: Negated character classes should usually be prefered over lazy matching, if possible. If the regex is successful, ^@[^@]*@ can match the content between @ s in a single step, while ^@.*?@ needs to expand for each

问题 I need to match @anything_here@ from a string @anything_here@dhhhd@shdjhjs@ . So I'd used following regex. ^@.*?@ or ^@[^@]*@ Both way it's work but I would like to know which one would be a better solution. Regex with non-greedy repetition or regex with negated character class? 回答1: Negated character classes should usually be prefered over lazy matching, if possible. If the regex is successful, ^@[^@]*@ can match the content between @ s in a single step, while ^@.*?@ needs to expand for each

问题 I try to understand the non-greedy regex in python, but I don't understand why the following examples have this results: print(re.search('a??b','aaab').group()) ab print(re.search('a*?b','aaab').group()) aaab I thought it would be 'b' for the first and 'ab' for the second. Can anyone explain that? 回答1: This happens because the matches you are asking match afterwards . If you try to follow how the matching for a??b happens from left to right you'll see something like this: Try 0 a plus b vs

问题 I am trying to capture matches between two strings. For example, I am looking for all text that appears between Q and XYZ, using the "soonest" match (not continuing to expand outwards). This string: circus Q hello there Q SOMETEXT XYZ today is the day XYZ okay XYZ Should return: Q SOMETEXT XYZ But instead, it returns: Q hello there Q SOMETEXT XYZ Here is the expression I'm using: Q.*?XYZ It's going too far back to the left. It's working fine on the ride side when I use the question mark after

问题 I need to get the value inside some tags in a comment php file like this php code /* this is a comment !- <titulo>titulo3</titulo> <funcion> <descripcion>esta es la descripcion de la funcion 6</descripcion> </funcion> <funcion> <descripcion>esta es la descripcion de la funcion 7</descripcion> </funcion> <otros> <descripcion>comentario de otros 2a hoja</descripcion> </otros> -! */ some php code so as you can see the file has newlines and repetions of tags like <funcion></funcion> and i need to