Add func to find pattern in file that spreads over multiple lines
The func will remove commented lines (that begin with '#')
and consider the file as one long line.
Thus, this is not possible to look for pattern at beginning of line
with this func ('^' and '$')
Improved pattern in 8.2.5
Add syslog-ng to installed dependencies in Dockerfiles
Fixed multifile arguments when looking for pattern that got broken
in d2bbf754 due to "nocase" and _does_pattern_exist_in_file wrapper
Please note that you can only look for pattern in ONE FILE at once
Fixed 8.2.5 and 8.3.2 with for loop on files and 'FOUND' flag
You now need to specify each and every file to look for or embed a
'find' command as follow :
`FILES="$SYSLOG_BASEDIR/syslog-ng.conf $(find $SYSLOG_BASEDIR/conf.d/)"`
Improved test files
Applied shellcheck recommendations
