Consider the following snippet: puts 'hello'.gsub(/.+/, '\0 \\0 \\\0 \\\\0') This prints (as seen on ideone.com): hello hello \0 \0 This was very surprising, because I'd expect to see something like this instead: hello \0 \hello \\0 My argument is that \ is an escape character, so you write \\ to get a literal backslash, thus \\...
I have a string, say r"a". I want to replace every r"a" with the string r"\1", but my regex engine does not understand this. I have tried: r"\1" -- crashes (can't match group 1 because there is no group 1) r"\\1" -- crashes (not sure why) Is this a limitation of my (proprietary) regex engine, or is it a general problem? Is there an ...
Is there a way to modify the value of a backreference? Example: In the following Text "this is a test" the word 'test' should be extracted and inserted into another text via backrefrence. Regex: (test) Replacement: "this is another \1" That works fine so far. But now the question is, if it is possible to modify the backreferen...
I'm having trouble with a regular expression in PHP that uses a potentially empty backreference. I was hoping that it would work as explained in http://www.regular-expressions.info/brackets.html: If a backreference was not used in a particular match attempt (such as in the first example where the question mark made the first ba...
string.replace(/([\t])/g,"\\$1") is working fine where string.replace(/([\n])/g,"\\$1") is not working!!! any idea please??? N.B. string.replace(/\n/g,"\\n") is also working fine ...
All, I've come across an interesting little quirk in one of my RewriteRules, which I wanted to resolve by the use of named back references. However from what I can see, this is not possible in Apache's mod_rewrite. I have two incoming urls, each containing a key variable, which need to be rewritten to the same underlying framework acti...