Renaming Groups of Files From the Command Line

FAIL (the browser should render some flash content, not this).


Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Trying to figure how the command works

Anonymous's picture

Enjoyed the video

I can see the removal of the parts, but not the re-arrangement.

Ok, finally figured out the following:
1) The command uses "substring removal" / "parameter substitution". Took awhile to find this out - my first search term was " ${f# " and got stuff on F# prog language. Live and Learn.
2) The " f# " is for removing the shortest prefix (ie, from the left).
3) The " f$ " is for removing the shortest prefix (ie, from the right).

Problem Restated:
1) Where in the command does it say ----> move the " aa " from the the beginning to the end of the filename?

Correction to the video
1) " f# " is for removing the shortest _not_ the longest prefix

Link that was helpful: Linux Journal Article

I really enjoy learning about the CLI:) and look forward to these videos.


Renaming Details

Mitch Frazier's picture

First, if I said "longest" I mis-spoke: "#" and "%" remove the "shortest" match, "##" and "%%" remove the longest match.

The rename command is this:

   mv -i $f 2009${f#*-2009}-${%-2009*}

There are 4 parts to the final file name:

   2009                # Literal
   ${f#*-2009}         # Based on original name
   -                   # Literal
   ${f%-2009*}         # Based on original name

Given the name "aa-2009-01-01". The first substitution removes the shortest prefix that matches "*-2009", in this case that prefix is "aa-2009", leaving "-01-01". The second substitution removes the shortest suffix that matches "-2009*", in this case that suffix is "-2009-01-01", leaving "aa". So the final name is formed from:

   2009                ==> 2009
   ${f#*-2009}         ==> -01-01
   -                   ==> -
   ${f%-2009*}         ==> aa

Resulting in the file name "2009-01-01-aa", the desired result.

Mitch Frazier is an Associate Editor for Linux Journal.


Anonymous's picture

I got it!
Very Clever
That was a surprisingly quick reply - Thanks


Ways's picture

rename 's/foo/bar/g' *

rename .oldextension .newextension *.oldextension

mmv 'banana_*_*.asc' 'banana_#2_#1.asc'

Bulk renaming :

You can also use "rename" command

apexwm's picture

The "rename" command offers as way to directly do essentially the same thing. It does a find/replace of the groups of files you specify.

Only in a few cases

Mitch Frazier's picture

Rename will work for you in some cases but not all, specifically it wouldn't work for the example in the video, unless I'm missing something...

Mitch Frazier is an Associate Editor for Linux Journal.

rename will work with

jimi's picture

rename will work with regex...

    rename s/\(..\)-\(.*\)/\$2-\$1/ *2009*

... but I never considered this usage of parameter substitution. Thanks!

One Click, Universal Protection: Implementing Centralized Security Policies on Linux Systems

As Linux continues to play an ever increasing role in corporate data centers and institutions, ensuring the integrity and protection of these systems must be a priority. With 60% of the world's websites and an increasing share of organization's mission-critical workloads running on Linux, failing to stop malware and other advanced threats on Linux can increasingly impact an organization's reputation and bottom line.

Learn More

Sponsored by Bit9

Linux Backup and Recovery Webinar

Most companies incorporate backup procedures for critical data, which can be restored quickly if a loss occurs. However, fewer companies are prepared for catastrophic system failures, in which they lose all data, the entire operating system, applications, settings, patches and more, reducing their system(s) to “bare metal.” After all, before data can be restored to a system, there must be a system to restore it to.

In this one hour webinar, learn how to enhance your existing backup strategies for better disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible bare-metal recovery solution for UNIX and Linux systems.

Learn More

Sponsored by Storix