regex to exclude string unless another string exists - regex

I'm currently working on a fluentd regex expression to match all log entries unless the message contains the string "dbug". However, if the log contains both "dbug" and "firing" in the entry then I need the regex to match that string.
The two strings can appear anywhere in the log entry however "dbug" will always be before "firing".
Is it possible to build a single regex expression that can do this?
I'd appreciate any help on this!

We can try using lookaheads here, e.g.
^(?:(?!.*\bdbug\b)|(?=.*\bdbug\b.*\bfiring\b)).*$
Demo
The first lookahead (?!.*\bdbug\b) matches any line which does not contain dbug at all, and the second lookahead (?=.*\bdbug\b.*\bfiring\b) matches any line which contains both dbug and firing, in that order.

Related

Regular Expression - Starting and ending with, and contains specific string in the middle

I would like to generate a regex with the following condition:
The string "EVENT" is contained within a xml tag called "SHEM-HAKOVETZ".
For example, the following string should be a match:
<SHEM-HAKOVETZ>104000514813450EVENTS0001dfd0.DAT</SHEM-HAKOVETZ>
I think you want something like this ^<SHEM-HAKOVETZ>.*EVENT.*<\/SHEM-HAKOVETZ>$
Regular expression
^<SHEM-HAKOVETZ>.*EVENTS.*<\/SHEM-HAKOVETZ>$
Parts of the regular expression
^ From the beginning of the line
<SHEM-HAKOVETZ> Starting tag
.* Any character - zero or more
EVENT Middle part
<\/SHEM-HAKOVETZ>$ Ending part of the match
Here is the working regex.
If you want to match this line, you could use this regex:
<SHEM-HAKOVETZ>*EVENTS.*(?=<\/SHEM-HAKOVETZ>)
However, I would not recommend using regex XML-based data, because there may be problems with whitespace handling in XML (see this article for more information). I would suggest using an actual XML parser (and then applying the reg to be sure about your results.
Here is a solution to only match the "value" part ignoring the XML tags:
(?<=<SHEM-HAKOVETZ>)(?:.*EVENTS.*)(?=<\/SHEM-HAKOVETZ>)
You can check it out in action at: https://regex101.com/r/4XiRch/1
It works with Lookbehind and Lookahead to make sure it will only match if the tags are correct, but for further coding will only match the content.

How to get the queryparam vid from the url using regex

Help me with the regex, I am trying to get the vid value from the following url.
I tried with like the following but I am not sure with that:
[\&]{1}vid[\=][\d]*
Is that correct?
Use vid=(\d+) for numbers of IDs see regex
Try Your Regex on this place...
https://regex101.com/r/dX3hD4/1
The trick here is to match between two patterns of interest -
"vid="
"&"
Anything you capture between that is what you're after.
Hence use this:
"http://gorid.com/api.jsp?acs=123&vid=432&skey=asdasd-asdas-adsasd".match("vid=([^;]*)&")[1]
We're accessing the 2nd element of the match object because that contains the value.
In a JS/PHP type environment, you can match on something like this, where you just find anything alphanumeric is between vid= and the following &:
vv = str.match(/vid=(.+?)&/)[1];
HERE
If the value is always numeric, replace (.+?) with (\d+?)
The regex you wrote will not work because you are including the characters &vid= in the return value. To make sure the regex engine checks for the string &vid= but does not include it in the result you will need to use a lookbehind:
(?<=&vid=)([^&\r\n]+)
We use a positive lookbehind to find &vid= and then grab everything from that point until the next & sign or the end of the line.
For your second request, if you wish to verify that the content of vid is a valid number you need to specify that all the characters following &vid= should be digits and also include a positive lookahead that makes sure the next character after the digits is a & sign. The corresponding regular expression then becomes:
(?<=&vid=)([^\D]+)(?=&)

Extracting address with Regex

I'm trying to looking for Street|St|Drive|Dr and then get all the contents of the line to extract the address:
(?:(?!\s{2,}|\$).)*(Street|St|Drive|Dr).*?(?=\s{2,})
.. but it also matches:
Full match 420-442 ` Tax Invoice/Statement`
Group 1. 433-435 `St`
Full match 4858-4867 `163.66 DR`
Group 1. 4865-4867 `DR`
Full match 11053-11089 ` Permanent Water Saving Plan, please`
Group 1. 11077-11079 `Pl`
How do i match only whole words and not substrings so it ignores words that contain those words (the first match for example).
One option is to use the the word-boundary anchor, \b, to accomplish this:
(?:(?!\s{2,}|\$).)*\b(Street|St|Drive|Dr)\b.*?(?=\s{2,})
If you provide an example of the raw text you're parsing, I'll be able to give additional help if this doesn't work.
Edit:
From the link you posted in a comment, it seems that the \b solution solves your question:
How do i match only whole words and not substrings so it ignores words that contain those words (the first match for example).
However, it seems like there are additional issues with your regex.

How to exclude a certain word in regex?

I'm using this expression and it's perfect for what I need:
.*(cq|conquest).*
It returns any word/phrase/sentence/etc. with the letters 'cq' or the word 'conquest' in it. However, from those matches I want to exclude all that contain the term 'conquest power'.
Examples:
some conquest here (should match)
another cq with some conquest here (should match)
too much cq or conquest power is bad (should not match)
How can I do that to the regex above? It has to be only one regex otherwise the program that I'm using (Advanced Combat Tracker) will create two different tabs.
If you want to match any string which contains "conquest" or "cq", but not if the string contains "conquest power", then the regex is
^(?!.*conquest power).*?(?:cq|conquest).*
The above will attempt to match from the start of the string to the end of the line, if you want to match from the start of each line, switch on multiline mode if available - adding (?m) to the start of the regex may do that.
If you want to match across newlines change . to [\s\S], or switch on singleline mode if available.
You have confused people by stating "I want to match 'cq' or 'conquest'" but also "I want the regex to extract that line".
I assume you don't really want to match just "cq" or "conquest", you want to match strings/lines (?) containing "cq" or "conquest".
From your original question I got that you want to match all strings which contain "cq" or "conquest" but do not contain "power". For this case the following regexp works:
^([^p]|p(?!ower))*(cq|conquest)([^p]|p(?!ower))*$
(regexpal)

regular expression matching issue

I've got a string which has the following format
some_string = ",,,xxx,,,xxx,,,xxx,,,xxx,,,xxx,,,xxx,,,"
and this is the content of a text file called f
I want to search for a specific term within the xxx (let's say that term is 'silicon')
note that the xxx can all be different and can contain any special characters (including meta characters) except for a new line
match = re.findall(r",{3}(.*?silicon.*?),{3}", f.read())
print match
But this doesn't seem to work because it returns results which are in the format:
["xxx,,,xxx,,,xxx,,,xxx,,,silicon", "xxx,,,xxx,,,xxx,,,xxsiliconxx"] but I only want it to return ["silicon", "xxsiliconxx"]
What am I doing wrong?
Try the following regex:
(?<=,{3})(?:(?!,{3}).)*?silicon.*?(?=,{3})
Example:
>>> s = ',,,xxx,,,silicon,,,xxx,,,xxsiliconxx,,,xxx'
>>> re.findall(r'(?<=,{3})(?:(?!,{3}).)*?silicon.*?(?=,{3})', s)
['silicon', 'xxsiliconxx']
I am assuming that the content in the xxx can contain commas, just not three consecutive commas or it would end the field. If the content in the xxx sections cannot contain any commas, you can use the following instead:
(?<=,{3})[^,\r\n]*?silicon.*?(?=,{3})
The reason your current approach doesn't work is that even though .*? will try to match as few characters as possible, the match will still start as early as possible. So for example the regex a*?b would match the entire string "aaaab". The only time the regex will advance the starting position is when the regex fails to match, and since ,,, can be matched by the .*?, your match will always start at the beginning of the string or just after the previous match.
The lookbehind and lookahead are used to address the issue raised by JaredC in comments, basically re.findall() won't return overlapping matches, so you need the leading and trailing ,,, to not be a part of the match.