How to remove lines from text file not starting with certain characters (sed or grep) -

how delete lines in text file not start characters #, & or *? i'm looking solution using sed or grep.

deleting lines:

with grep

the grep command selects , prints lines file (or bunch of files) match pattern.

i think can this:

grep -v '^[\#\&\*]' yourfile.txt > output.txt

you can use sed same thing (check http://lowfatlinux.com/linux-sed.html ):

sed '^[\#\&\*]/d' yourfile.txt > output.txt

it's decide

filtering lines:

my mistake, understood wanted delete lines. if want "delete" other lines (or filter lines starting specified characters), grep way go:

grep '^[\#\&\*]' yourfile.txt > output.txt

Ben