I'm working on a PowerShell script that requires distinguishing between different types of lines based on their contents. Specifically, I need to identify lines that may contain square brackets, but I want to avoid lines that are fully enclosed in brackets. Here are the categories I'm focusing on:
1. Lines that are fully enclosed in square brackets, like `[section line]`.
2. Lines containing an equal sign, such as `key = value`.
3. All other lines, including those with square brackets inside them, like `No4 how to match [this] line along with lines No2 and No3`.
I've created some patterns to match these cases, but I'm struggling with the third case, especially when a line has square brackets inside it. My initial regex attempts, like using negative lookaheads and lookbehinds, haven't worked. Any suggestions on how to effectively capture lines that contain inner brackets without matching the ones that are entirely enclosed?
4 Answers
Have you tried simplifying your approach using a switch statement? You can check for lines entirely enclosed in brackets first, and if not, check for equal signs. If a line contains brackets but isn't fully enclosed, you could identify that as well.
Regex can be powerful, but in this case, it's worth considering whether you really need it. You can split the lines and just check the conditions programmatically. Switching based on conditions might simplify your code without complicating it with regex.
Another option is to split the string into lines and then use a simple conditional check inside a switch statement. For instance, you can check if the first character is `[` and the last is `]`, then handle the equality separately, and default for others. It's straightforward and might work just as well without regex.
For your third pattern, you actually don't need lookaheads or lookbehinds. A simpler regex could do the trick. Try using `^[^[][^=]+[^]]$`, which matches lines like No2, No3, and No4 as intended. It seems to do the job you're looking for!
I changed my pattern for key=value from `(.+?)s*=(.*)` to `^([^=].+?)s*=(.*)` to avoid matching entries starting with '='. That fixed the issue for now!
Thanks for the suggestion! That pattern worked perfectly. However, I've encountered an issue where special cases like `=[*]=` get caught in both this and the original key=value pattern. I'm considering tweaking the key=value regex to exclude such cases. Any tips?
Yes, I like the idea of using a switch! I created a sample script to visualize how the matches work. Your approach really helps clarify how to structure my code effectively, and it worked great for the data I had!