Renaming directories with Regex? Possible?

smaddox · 09-08-2009, 11:39 PM

I spent the last hour trying to figure out how to do what seems like it should be a simple directory rename.

I have the following directories in the CWD:

Code:

2008F - EE325K - Antennas and Wireless Propagation
2008F - EE348 - Lasers and Optical Engineering
2009F - EE396V - Physical Principles of Electronic Materials
2009S - EE383V - Electromagnetic Metamaterials
2009S - EE464 - Senior Design Project
other.random.directory.or.Some.File

And I want to rename them to:

Code:

2008 Fall - EE325K - Antennas and Wireless Propagation
2008 Fall - EE348 - Lasers and Optical Engineering
2009 Fall - EE396V - Physical Principles of Electronic Materials
2009 Spring - EE383V - Electromagnetic Metamaterials
2009 Spring - EE464 - Senior Design Project
other.random.directory.or.Some.File

(Note: this is just a representative sample)

The closest I got was the following command:

Code:

ls|grep 200|sed -e 's/2008F/2008 Fall/g' -e 's/2009F/2008 Fall/g' -e 's/2009S/2009 Spring/g'

but all this does is print out the new names. Is there a way to feed it and the prior name into mv?

Alternatively (possibly preferrably) is there a better way to do this? Consider it a puzzle =)

Thanks!

kbp · 09-09-2009, 12:39 AM

Something like:

Code:

for file in $(ls -1)
do
  if [[ "${file}" =~ '200[89][FS].*' ]]
  then
     newfilename=$(sed .... )
     mv $file $newfilename
  fi
done

(not tested at all)

btw.. thats a (one) not an (ell) in the first line

cheers

kbp

Tinkster · 09-09-2009, 01:38 AM

Quote:

btw.. thats a (one) not an (ell) in the first line

I don't think the -1 is actually needed ...

Cheers,
Tink

smaddox · 09-09-2009, 06:48 PM

Thanks for putting me on the right direction! I learned a lot.

Your code didn't really work for a couple of reasons though.
1) The for loop uses spaces as field separators
2) the regex should not be in quotes unless you want it to be literal

I found the solution for the reverse problem (tested with echo in place of mv):

Code:

ls -1 | while read file; do 
  if [[ $file =~ (200[89])\ (Fall|Spring)(.*) ]]; then  
    mv "'$file' '${BASH_REMATCH[1]}`echo ${BASH_REMATCH[2]}|cut -c1`${BASH_REMATCH[3]}'";
  fi;
done

That was far more difficult than I expected, but I think next time I have something similar I might be able to do it fairly quickly. =)

Thanks again.

chrism01 · 09-10-2009, 02:15 AM

Note that 'The for loop uses spaces as field separators' is typical for almost all *nix utils ie space is seen as an arg separator, that's why you don't usually see spaces in (pre-supplied) filenames.
Causes too much hassle.

smaddox · 09-10-2009, 08:56 AM

What annoyed me was that neither escaping the spaces (ls -b), nor surrounding the filenames in quotes (ls -Q) worked. The for loop would still separate a the space. It seems to me that quotes should have worked since they aren't allowed in file names, and passed as arguments they would be there to group words.

Was there something I missed?

chrism01 · 09-11-2009, 01:57 AM

I'd alter the IFS value to just a newline. By default its space or tab or newline.
You may need to restore it to the std values after the loop if you're going to do more processing in the script.
http://tldp.org/LDP/abs/html/internalvariables.html

archtoad6 · 11-09-2009, 05:40 PM

rename works on directories too. The only trick needed to keep it from changing the name of similarly named files seems to be using a trailing '/':

Code:

rename 's,(200.)F,$1 Fall,' 200*/

should do what you want. -- I tested on a recreation of your sample.
Lather, rinse, repeat for the other 3 seasons.

from the man page:

Quote:

SYNOPSIS
rename [ -v ] [ -n ] [ -f ] perlexpr [ files ]

Remember that the perlexpr is a perl expression, while the optional files entry uses bash globbing -- i.e. the wildcarding is totally different.

Final Note: Spaces in *nix file (& directory) names can cause problems -- it's a bad practice.

ghostdog74 · 11-09-2009, 06:27 PM

Quote:

Originally Posted by kbp

Something like:

Code:

for file in $(ls -1)
do

kbp

no need ls.....

Code:

for file in *

ghostdog74 · 11-09-2009, 06:34 PM

if you have Python 2.4+ and don't mind, you can use use this script

usage:

Code:

$ ls -1
2008F - EE325K - Antennas and Wireless Propagation
2008F - EE348 - Lasers and Optical Engineering
2009F - EE396V - Physical Principles of Electronic Materials
2009S - EE383V - Electromagnetic Metamaterials
2009S - EE464 - Senior Design Project

$ filerenamer.py -t d -p "200([89])F" -e "200\1 - Fall" -l "200[89]F*"
=>>>>  [ /home/2008F - EE325K - Antennas and Wireless Propagation ]==>[ /home/2008 - Fall - EE325K - Antennas and Wireless Propagation ]
=>>>>  [ /home/2009F - EE396V - Physical Principles of Electronic Materials ]==>[ /home/2009 - Fall - EE396V - PhysicalPrinciples of Electronic Materials ]
=>>>>  [ /home/2008F - EE348 - Lasers and Optical Engineering ]==>[ /home/2008 - Fall - EE348 - Lasers and Optical Engineering ]

Do another time for spring

Code:

filerenamer.py -t d -p "200([89])S" -e "200\1 - Spring" -l "200[89]S*"

remove -l option to commit changes