For example, I had a .g4 of calculating expressions. ANTLR4 can parse any valid input of calculation expression as a parser tree. I'm considering the following scenario.
Without any input, is it possible to generate the new valid calculation expressions based on ANTLR4? It should be a grammar-based generator.
Does anyone have a suggestion about how to build a grammar-based generator with ANTLR4?
Thanks in advance!
Related
I find it very hard to use regular expressions directly in the search bar to extract fields. Another problem is that I do not have the permission to share my extracted fields (extracted by the field extractor and stated in field extractions) with other people. I am now looking for another way to extract fields directly in the search bar. Is there something like this possible in Splunk?
Thanks!
Regular expressions aren't so bad once you've had some practice. Think of them as another programming language to know.
There are other ways to extract fields, but most are less efficient and all are less flexible.
The spath and xpath commands will extract fields from JSON and XML, respectively.
multikv extracts fields from table-formatted data (like from top).
The extract command can be used to parse key/value pairs into fields.
The eval command can be used in combination with various functions to parse events into fields.
I'm using Screaming Frog as a way to extract data from a Json generated from an URL.
The Json generated is this form :
{"ville":[{"codePostal":"13009","ville":"VAUFREGE","popin":"ouverturePopin","zoneLivraison":"1300913982","url":""},{"codePostal":"13009","ville":"LES BAUMETTES","popin":"ouverturePopin","zoneLivraison":"1300913989","url":""},{"codePostal":"13009","ville":"MARSEILLE 9EME ARRON","popin":"ouverturePopin","zoneLivraison":"1300913209","url":""}]}
I'm using this regex in Custom > Extraction in Screaming Frog as a way to extract the values of "codePostal".
"codePostal":".*?"
Problem is it doesn't extract anything.
When I test my regex in regex101, it seems correct.
Do you have any clue about what is wrong ?
Thanks.
Regards.
Have you tried to save the output to understand what ScreamingFrog sees? It doesn't matter - not at the beginning - whether your RegEx works.
That said, don't forget that SF is a Java based tool hence it is the engine used by the reg ex, so make sure you test your regular expressions with the correct dialect.
You need to specify group extractors enclosed in parentheses. For instance in your example, you need to have ("codePostal":".*?") as extractor.
In addition if you simply want to extract the value, you could use the following instead.
"codePostal":"(.*?)"
It's not a problem with your Regular Expression. It seems to be that the problem is with the Content Type. ScreamingFrog isn't properly reading application/JSON content types for scraping. Hopefully they will fix this bug.
I just came across a JSON wannabe that decides to "improve" it by adding datatypes... of course, the syntax makes it nearly impossible to google.
a:4:{
s:3:"cmd";
s:4:"save";
s:5:"token";
s:22:"5a7be6ad267d1599347886";
}
Full data is... much larger...
The first letter seems to be a for array, s for string, then the quantity of data (# of array items or length of string), then the actual piece of data.
With this type of syntax, I currently can't Google meaningful results. Does anyone recognize what god-forsaken language or framework this is from?
Note: some genius decided to stuff this data as a single field inside a database, and it included critical fields that I need to perform aggregate functions on. The rest I can handle if I can get a way to parse this data without resorting to ugly serial processing.
If this can be parsed using MSSQL 2008 that results in a view, I'll throw in a bounty...
I would parse it with a UDF written in .NET - https://learn.microsoft.com/en-us/sql/relational-databases/clr-integration-database-objects-user-defined-functions/clr-user-defined-functions
You can either write a custom aggregate function to parse and calculate these nutty fields, or a scalar value function that returns the field as JSON.
I'd probably opt for the latter in the name of separation of concerns.
I need a regular expression to extract a value from a given key/value pair. It's not for a specific language. A working example in https://regex101.com/ would be great.
Here's what I get:
{"task_id":"12323232-323-23-321"}
and here's what I expect:
12323232-323-23-321
I know, it looks easy, but drives me crazy.
The perfect solution would be:
"return the value for task_id"
.
Thanks in advance
Adam
Don't know why would you want to use regex in this case since you're dealing with json. It's unlikely that the language you're using would not have a support / library for json, which would allow you to extract the task_id.
Getting back to regex you could try capturing a group.
:"(.*?)"
Currently testing system where the output is in the form of formatted json.
As part of my tests I need to extract and validate two values from the json record.
The values both have individual identifiers on them but don't appear in the same part of the record, so I can't just grab a single long string.
Loose format of the information in both cases:
"identifier1": [{"identifier2":"idname","values":["bit_I_want!]}]
In the case of the bit I want, this can either be a single quoted value (e.g. "12345") or multiple quoted values (e.g. "12345","23456","98765").
In both cases I'm only interested in validating the whole string of values, not individual values from the set.
Can anyone recommend which of the various extractors in Jmeter would be best to achieve this?
Many Thanks!
The most obvious choicse seems to be JSON Path Assertion (available via JMeter Plugins), it allows not only executing arbitrary JSON queries but conditionally failing the sampler basing on actual and expected result match.
The recommended way of installing JMeter Plugins and keeping them up-to-date is using JMeter Plugins Manager
JMeter 3.1 comes with JSON Extractor to parse JSON response. you could use this expression $.identifier1[0].values
as the JSON Path to extract the values.
If your JSON response is going to simple always as shown in your question, you could use Regular Expression Extractor as well. Advantage is it is faster than JSON extractor. The regular expression would be "values":\[(.*?)\]
Reference: http://www.testautomationguru.com/jmeter-response-data-extractors-comparison/