I'm trying capture mount options in fstab config with python regex module for /tmp LV.
This is how the config looks like:
/dev/mapper/rootvg-lv_home /home ext4 nosuid,nodev 1 2
/dev/mapper/rootvg-lv_opt /opt ext4 nosuid,nodev 1 2
#/dev/mapper/rootvg-lv_tmp /tmp ext4 nosuid,noexec 1 2
/dev/mapper/rootvg-lv_tmp /tmp ext4 nosuid,nodev 1 2
/dev/mapper/rootvg-lv_var /var ext4 nosuid,nodev 1 2
So I need to capture only options "nosuid,nodev" from this line:
/dev/mapper/rootvg-lv_tmp /tmp ext4 nosuid,nodev 1 2
I tried this:
(?<=\s+\/tmp\s+ext4\s+)(\,|[a-z])+(?=\s+[0-9])
But it also caputures commented line.
Even worse python re module can't run this regex expression because of this problem with lookbehind The contained pattern must only match strings of some fixed length, meaning that abc or a|b are allowed, but a* and a{3,4} are not.
-source: https://docs.python.org/3/library/re.html
If I try to run it with current regex this error will popup
look-behind requires fixed-width pattern
How should I construct regex expression for this?
I visited a few sites such as:
Python regex error: look-behind requires fixed-width pattern
Python Regex Engine - "look-behind requires fixed-width pattern" Error
But I wasn't able to construct anything that would work for my kind of problem.
How about a regex like this?
^[^\s#]+\s+/tmp\s+\S+\s+(\S+)
No lookaround, matches only /tmp, and captures the options into group 1. Avoids matching the commented line by saying that the first field may contain any character which is not whitespace or #.