How to remove last directory from a path with sed (not using dirname)?

Question

How to remove the last dir with sed, like this:

echo "/dir1/dir2/dir3/dir4" | sed .....

So I would get /dir1/dir2/dir3.

Answer 1

sed 's,/*[^/]\+/*$,,'

If it's part of the shell script, then dirname will be definitely more clear.

Answer 2

echo "/etc1/etc2/etc3/etc" | sed -e "s/\/[^\/]*$//"

produces

/etc1/etc2/etc3

Basically strip off anything at the end after the last slash that doesn't contain another slash.

Answer 3

you don't have to use external tools

$ a="/dir1/dir2/dir3/dir4"

$ echo ${a%/*}