My professor sent us this little one liner (ok, I had to format it to 2 lines to fit in this blog. You know what I mean) which prints out the current directory tree:

ls -R | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' \
-e 's/^/ /' -e 's/-/|/'

What’s going on here?

• ls -R — list files and directories recursively
• grep ":$" — find lines with : at the end (so only the directories)
• sed -e — evaluate expressions on the lines
• s/:$// — remove ‘:’ at the end of the line
• s/[^-][^\/]*\//--/g — replaces text between / / lines (parent directories) with — , globally on each line
• s/^/ / — add space at the beginning of the lines
• s/-/|/ — replace first – of the line with |

I reduced this using the following command. The most notable difference is that I use find instead of ls, which results in also viewing .hidden directories. I’m not sure which command is faster.

find ./ -type d | sed -e 's/[^-][^\/]*\//--/g;s/--/ |-/'

Both commands result in a formatted directory listing, demonstrated below:

|-sitetransfer
 |---redacteddomain.com
 |-----cache
 |-----templates
 |-------skidoo_too
 |---------images
 |-----------_vti_cnf
 |---------css
 |-----------_vti_cnf
 |---------js
 |-----------scriptaculous
 |-------------src
 |-------------lib
 |---------admin_templates

Tagged: bash, sed