In our Splunk forwarder, in the path: /opt/splunk/etc/apps/app01/default we have many stanzas such as:
[monitor:///export/data/syslog-ng/sentry*/messages]
disabled = false
host_regex = /export/data/syslog-ng/(.*?)/messages
index = asalg
sourcetype = cisco_asa
And under every stanza there is the following line:
host_regex = /export/data/syslog-ng/(.*?)/messages
I am very curious to know what the "/(.*?)/" means?
Thank you.
The host_regex is used to extract the hostname from the monitored path. In regular expressions (...)
denotes a capturing group, so that is what actually captures the hostname, from that part of the path. The .*?
means that it accepts all kinds of characters for the hostname, but using the ?
it only captures things until it actually finds something that matches what comes after the ?
. In this case the "/messages" bit.
The host_regex is used to extract the hostname from the monitored path. In regular expressions (...)
denotes a capturing group, so that is what actually captures the hostname, from that part of the path. The .*?
means that it accepts all kinds of characters for the hostname, but using the ?
it only captures things until it actually finds something that matches what comes after the ?
. In this case the "/messages" bit.
Thanks FriankVI !