sed: How to delete lines matching a pattern that contains forward slashes?

Question

Suppose a file /etc/fstab contains the following:

/dev/xvda1 / ext4 defaults 1 1
/dev/md0    /mnt/ibsraid    xfs defaults,noatime    0   2
/mnt/ibsr         


        

Answer 1

Why the obsession with using forward slash as your delimiter? Just use something else, like a comma:

sed ',^/dev/xvdb,d' /etc/fstab

or a colon:

sed ':^/dev/xvdb:d' /etc/fstab

Or whatever makes it easiest to read. The delimiter can be any character. The convention is to use a forward slash, but when it becomes awkward, switch it to something else.

Note, if you want to change the file itself, rather than output the result, you need the "in place" flag -i:

sed -i ':^/dev/xvdb:d' /etc/fstab