Regular Expression match only beginning of string - regex

I'm trying to match a regular expression on a string that has multiple matches, but i want to match the first occurrence and i'm expecting my match only in the beginning of the string
E.g.: 4_12052022_01.abc
in the above "4" is my target for a match.
But my string can also have something like 1_231233_4_43.abc, so here it should not match the occurrence of 4 because it's not in the beginning of the string.
I'm using SyncbackPro v9 and want to setup filtering through regex.
What i have tried and doesn't seem to work for me
4_.*, this matches both the strings above
^4_.*, this tests fine in most of the online regular testing websites, but in syncback it doesn't work.

Related

Matching complex regular expression containing regex expression and not containing another string

I am trying to match through regex a string that contains a certain regex pattern and doesn´t contain a substring. However this substring needs to be in a certain location of the string fitting rest of the pattern
I am trying to do this regex
^(-?NODE1-METHOD1-NODE2-).*(?!NODE3)-METHOD2-+
Where I will match all the strings containing NODE1-METHOD1-NODE2- followed by whatever character and that won't have NODE3 and that finally will have METHOD2 followed by -
This regex would match the following string
NODE1-METHOD1-NODE2-METHOD4-NODE5-METHOD5-NODE6-METHOD6-NODE6-METHOD7-NODE7-METHOD2----------------------------
but not this one
NODE1-METHOD1-NODE2-METHOD4-NODE5-METHOD5-NODE3-METHOD2----------------------------
Right now, with the pattern I'm using, I'm not able to match any of the cases.
Happy to study other ways to do this.
Thanks
Using this part in your pattern .*(?!NODE3)-METHOD2-+ the .* will first match until the the end of the string followed by (?!NODE3) which will be true as it is as the end of the string and there is no NODE3 at the right.
You could check right after closing the first group that the rest of the string does not contain NODE3 using a negative lookahead with a quantifier inside it (?!.*NODE3)
If that succeeds, match any character until you encounter METHOD2 followed by 1 or more hyphens .*METHOD2-+
^(-?NODE1-METHOD1-NODE2-)(?!.*NODE3).*METHOD2-+
Regex demo

pick up specific words from string using regex match

I want to pick up specific word from below string using regex. I need to match query and secondstring. I have regex like
(\w+)\s*\{([^(]+)\((.*)
{"querys":"query{secondstring(input:{
For above it works fine. But i will have to match below also using same regex.
{"query":"query{helloworld {sdsd
You can see that there is a space and { instead of (.

Match everything but Regular Expression

Been searching for a long time, reading up about negative/positive outlook but can't get this to match everything but my regular expression.
\b[A-Z]{1}\d{3,6}[A-Z0-9]+
is the string I don't want to extract.
(?!\b[A-Z]{1}\d{3,6}[A-Z0-9]+).*
is my best attempt using Negative Outlook, but it will still match the data.
I am using this Regex on:
11/02/2019 1 475.50 453.345 Serial number : C580A0453WD7996 
AFJ_LowGuard_NewNew
End User Details:
The output I want is:
11/02/2019 1 475.50 453.345 Serial number :
AFJ_LowGuard_NewNew
End User Details:
You can either use your regex to match and replace the match with empty string, that's one approach.
Another approach that you seem to be trying is, you can use this following regex to match anything but your regex,
\b(?:(?![A-Z]\d{3,6}[A-Z0-9]+).)+\b
Demo
This will match anything except your pattern. But personally I suggest replacing by matching your pattern should be easy.
Edit:
Ok I read your comment that you want to replace anything except the string matched by your pattern. In that case you can use following regex to match everything except your pattern and replace it with empty string to get your result,
\b(?:(?![A-Z]\d{3,6}[A-Z0-9]+).)+
Demo with replacement with empty string

Regex - Match the pattern of a string representing a variable and its assigned value

I am trying to find a regex pattern that would enable me to swiftly search through my source code to find the following string pattern:
placeholder="any text here"
I have tried the following regex pattern however, it does not exclusively capture strings beginning with the sub-string "placeholder".
placeholder=\".+\"
You need to make lazy, with ?. Otherwise it captures the maximal possible match. Also, no need to escape the quotes.
placeholder=".+?"

Regular Expression extract substring (.)*

I am trying to match with the following regex.
\d{11}(.*)
Which is any 11 digits followed by a string. I want to extract the tailing string whatever it is.
I used RE2::FullMatch but it gives the first half (the 11 digits). How to get the sub-string matched with (.*) ?
string subStr
RE2::FullMatch("<sip:+19073381121#216.67.108.201:5060;user=phone>;npi=ISDN",(<sip:\+(\d{11}))(.*), &subStr);
I am trying to extract everything starting from # in above string. Basically I want what matches to (.*) but the above function returns <sip:+19073381121.
I am not very familiar with regex but I looked at different APIs to extract substrings and found this one usefull
Remove the extra capturing groups from your regular expression.
<sip:\+\d{11}(.*)
To get the sub string matched with (.*) use $1. That is the first capturing group that you specified with the brackets.