#! /bin/sed -f

# Put the indentation in hold space
/:$/ {
    h
    s,\.:,,
    s,[^/:]*[/:],  ,g
    x
}  

# Add the indentation in front of the line
G  
s:\(.*\)\n\(.*\):\2\1:

### colorized by sedsed, a debugger and code formatter for sed scripts
### original script: http://sed.sf.net/grabbag/scripts/indentls.sed