topic Re: RegEx Help Needed in Splunk Search

RegEx Help Needed

danfinan — Thu, 12 Sep 2019 14:51:25 GMT

Hi guys,

I'm a complete newbie when it comes to RegEx, but I was wondering if someone could please advise on how I could extract the name of the device from the following string?

"hostname"="iPhone"

The syslog I am using has every data point in the same format, I would like to make sure that Splunk correctly identifies the hostname each time. The built-in field extraction tool could recognise the term 'iPhone' but not something like 'DESKTOP-8HGF56' for example. I need it to be 100% every time so perhaps a regex term could let anything between "hostname"="xxxx" be extracted?

Any advice would be greatly appreciated, thank you!

Re: RegEx Help Needed

manuelostertag — Thu, 12 Sep 2019 15:31:59 GMT

Hi,

to "extract" the device name, please try this regex:

"\w.+"="(?P<device_name>.+)"

The value will be stored in device_name.

Here you can test the regex https://regex101.com/r/LNP0Ia/1

Re: RegEx Help Needed

gcusello — Thu, 12 Sep 2019 16:39:11 GMT

Hi danfinan,
try this

| rex "\"hostname\"\=\"(?<device_name>[^\"]*)\""

you can test it at https://regex101.com/r/kQZJQe/1

Bye.
Giuseppe

Re: RegEx Help Needed

jpolvino — Thu, 12 Sep 2019 17:50:22 GMT

Giuseppe uses a noteworthy tactic: matching on characters that are NOT something. In this case, matching on characters that are not double quotes. You may find that this is much more reliable that listing out the legal characters or character classes. I use this a lot and it has saved time by making the matching much more reliable.

Re: RegEx Help Needed

manuelostertag — Thu, 12 Sep 2019 18:14:24 GMT

Indeed, this regex solution is the better one 🙂

Re: RegEx Help Needed

gcusello — Fri, 13 Sep 2019 07:07:22 GMT

Hi danfinan,
if this answer satisfies your need, please accept and/or upvote it.
Bye and see next time.
Giuseppe

Re: RegEx Help Needed

danfinan — Mon, 16 Sep 2019 12:54:33 GMT

Giuseppe, you wonderful human - that worked perfectly, exactly what I was looking for. Thank you very much for your help, greatly appreciated!