Script: Nextcloud Log Filtering for usage within the shell

🏷️ General
1

I wrote a small bash script, which enables to search for words or exclude words in the nextcloud.log by attributes.

Some command examples:

  1. Show only log entries for username containing “peter”:
$ cat nextcloud.log \
   | nc-log-filter --search user:peter
  1. Show only log entries where username does neither contain “peter” nor “susan” nor the message containing “dirty table reads”
$ cat nextcloud.log \
   | nc-log-filter \
        --not user:peter \
        --not user:susan \
        --not message:"dirty table reads"
  1. Suppress all level 0 messages
cat nextcloud.log | nc-log-filter --not level:0

Using tail -f to watch output works fine too:

tail -f nextcloud.log | nc-log-filter –-search user:peter

NOTE:

The script is not tolerant to errors in key names.

Example output:

{
  "reqId": "jAN7l3ID4cntmPdEO530",
  "level": 0,
  "time": "2025-12-19T12:30:02+00:00",
  "remoteAddr": "",
  "user": "--",
  "app": "cron",
  "method": "",
  "url": "--",
  "message": "Finished job OCA\\Talk\\BackgroundJob\\CheckHostedSignalingServer (id: 49164, arguments: null) in 0 seconds",
  "userAgent": "--",
  "version": "32.0.2.2",
  "data": {
    "app": "cron"
  }
}
{
  "reqId": "yZYS2ihxlUUTH2DFOqJI",
  "level": 1,
  "time": "2025-12-19T12:32:07+00:00",
  "remoteAddr": "3.4.5.6",
  "user": "--",
  "app": "core",
  "method": "GET",
  "url": "/index.php",
  "message": "Trusted domain error. \"3.4.5.6\" tried to access using \"1.2.3.4\" as host.",
  "userAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:101.0) Gecko/20100101 Firefox/101.0",
  "version": "32.0.2.2",
  "data": {
    "app": "core"
  }
...

Script Source:

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