fail2ban/config/action.d/helpers-common.conf

[DEFAULT]

# Usage:
#   _grep_logs_args = 'test'
#   (printf %%b "Log-excerpt contains 'test':\n"; %(_grep_logs)s; printf %%b "Log-excerpt contains 'test':\n") | mail ...
#
_grep_logs = logpath="<logpath>"; grep <grepopts> -E %(_grep_logs_args)s $logpath | <greplimit>
_grep_logs_args = '(^|[^0-9])<ip>([^0-9]|$)'

[Init]
greplimit = tail -n <grepmax>
grepmax = 1000
grepopts = -m <grepmax>
fixed several actions, that could not work with jails using multiple logpath; additionally repaired execution in default shell (bad substitution by `${x//...}` executing in `/bin/sh`); added helper "action.d/helpers-common.conf", and `_grep_logs` part-command for actions needed grep logs from multiple log-files test cases: executing of some complex actions covered 8 years ago			`[DEFAULT]`

			`# Usage:`
			`# _grep_logs_args = 'test'`
			`# (printf %%b "Log-excerpt contains 'test':\n"; %(_grep_logs)s; printf %%b "Log-excerpt contains 'test':\n") \| mail ...`
			`#`
			`_grep_logs = logpath="<logpath>"; grep <grepopts> -E %(_grep_logs_args)s $logpath \| <greplimit>`
			`_grep_logs_args = '(^\|[^0-9])<ip>([^0-9]\|$)'`

			`[Init]`
			`greplimit = tail -n <grepmax>`
			`grepmax = 1000`
			`grepopts = -m <grepmax>`