Helps to search a line over a text file with ignoring (excluding from searching) the lines started with a # (hash) symbol
^([^#].*)?^\s*dev1
#| Environment | Port-prefix | Subnet | Target-host |
#dev1 300 8 ibdock2
# dev1 300 8 ibdock2
#dev1 300 8 ibdock2
# dev1 300 8 ibdock2
dev1 300 8 ibdock2
dev1 300 8 ibdock2
dev 301 1 ibdock2