Is this possible to use in MS Visual Studio using 'Edit->Find and Replace->Replace in files' and checking 'Use regular expressions' and if so, then what should be in boxes 'Find what' and 'Replace with:' ?
Lets say I want to "encrypt" the ID number 123456789 - add '*' to all the digits up to the last four - *****6789.
A starting point is to replace .*(....) with *$1. But it would produce *6789, which is too short.
How can I know how many chars the first .* matched?
It depends to a certain extent on what "non zero numbers" means, exactly. Does it mean 0only and exactly, or does it have to not match 0. 0.0 0.00 etc.
For the simple case of a just excluding a zero we can use the following perl regex:
I've anchored this on line start and end ^ ... $, but you might have other requirements. This will match e.g 1.2 -15 0.03 .12 15. and -0.3, and does not accept any of ., 0, 0., or 1.2.3. However it does accept 0.0, 0.00, etc, and I have not yet found a way to eliminate them from the pattern. There might be a way using lookahead/lookbehind matches Lookahead and Lookbehind Tutorial—Tips &Tricks, but so far I haven't been able to figure out how to tell the regex engine that the lookahead/behind should match the entire pattern. For example we can eliminate 0.0 by adding a negative lookbehind regex of (?<!0.0), but this also elminates 0.03, which is not what is wanted. Maybe someone else knows how to resolve this.
But maybe regex isn't the way to go. If you're working in Java or C# or C++ or ... , it's probably better to just read some input, check that the entire input parses as a number, convert to a number and then omit or complain if the value is zero - depending on what your use case is.
The problem is that your first \b is matching too early.
Try something like [A-Za-z]*bad boys[A-Za-z]*
In words, that will match "none or some alphabetic characters (no spaces!)" then "bad boys" then "none or some alphabetic characters"
Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012
What is Perl regex anchor to merely match at the position where the previous match ended, as anchor \G matches at the position where the previous match ended, and also at the first match attempt the \G matches at the start of the string in the way \A does.
In the meantime I think, I have found out, what the difference is between abc(?=.*xyz) and abc.*xyz
We have 4 elements:
1. The regex search command string
2. The strings (e.g. the names of the files).
3. The strings that had a result (e.g. the file names that have a result).
4. The result for each string (The match within each string)
2-3 are the same for both abc(?=.*xyz) and abc.*xyz.
But 4. is different.