I have a couple of big hard drives on my desktop PC. Still, from time to time I need to do some maintenance to get rid of all the junk I throw at them. Lately, I’ve been moving files around a lot. And I was doing it all wrong! I set the laziness aside and thought about ways of improving my “work flow”.

Whitespace, go away!

The first issue I had is that bash gets confused when the filenames include white space.


[emmanuel@going_merry ~/files]
$ ll
total 4
-rw-r--r-- 1 emmanuel users 2818 2009-08-11 11:38 This is my afn.py

[emmanuel@going_merry ~/files]
$ mv This is my afn.py afn.py
mv: target `afn.py’ is not a directory

[emmanuel@going_merry ~/files]
$ mv This\ is\ my\ afn.py afn.py

Notice the slashes I had to add on the second mv call. This might seem pretty obvious. Bash usually puts those slashes automatically when using tab completion. But the thing is, what I really need in my case is to move a whole set of files returned by other utility, like find, to another place:


[emmanuel@going_merry ~/files]
$ ll
total 8
drwxr-xr-x 2 emmanuel users 4096 2009-08-11 11:41 dir1
drwxr-xr-x 2 emmanuel users 4096 2009-08-11 11:41 dir2

[emmanuel@going_merry ~/files]
$ find dir1/
dir1/
dir1/My afn 1.py
dir1/My afn 2.py

[emmanuel@going_merry ~/files]
$ find dir1/ | xargs -I {} mv {} dir2
mv: cannot stat `dir1/My afn 1.py': No such file or directory
mv: cannot stat `dir1/My afn 2.py': No such file or directory

The problem here is in the find output. The list of  path names returned by find may have unescaped spaces on path names. I needed to escape those spaces before using those path names with other utilities. I looked around for a unix utility to help me in this regard, but not easily finding anything good around, I just wrote a little ruby script for dealing with this: "escapepath".


[emmanuel@going_merry ~/files]
$ which escapepath
/usr/bin/escapepath


[emmanuel@going_merry ~/files]
$ cat `which escapepath`


#!/usr/bin/ruby
require 'shellwords'

while not STDIN.eof?
  puts(STDIN.gets.chomp.shellescape)
end

gist

Now I can do things like:


[emmanuel@going_merry ~/files]
$ find dir1/ -type f | escapepath | xargs -I {} mv {} dir2/


---

If you are typing too much, you are not aliasing enough

An anti-pattern I was using was... typing a lot. I kept running again and again things like:

[emmanuel@going_merry ~/files]
$ ack -a -f | grep thing_i_want_to_find -i | escapepath | xargs -I {} mv {} /some/directory


...to find several files at once using a case insensitive regular expression and move all of them to a certain directory. The solution: bash aliases:


[emmanuel@going_merry ~/files]
$ cat ~/.bashrc

# ...
alias xmv='escapepath | xargs -I {} mv {}'
alias ifind='ack -a -f | grep -i'
# ...

Note: ack is a cool alternative to find+grep which also has some nice file finding features. Check it out.

Know I can do things like:


[emmanuel@going_merry ~/files]
$ ifind thing_i_want_to_rm | xargs rm
[emmanuel@going_merry ~/files]
$ ifind thing_i_want_to_move | xmv /some/directory


Ah! much more easy on my poor fingers....