How can I change the prefix of multiple files in a directory

6millionbucks · 07-31-2007, 12:47 AM

Hello All,

I have found ways to change file names, file extensions, uppercase to lowercase but I cant figure out how to change the prefix of multiple files in a directory using a script. For example:

Change file 1: "Favorites_Jan1998_CD01.1c.mp3" to "199801_Favorites_CD01.1c.mp3"

Change file 2: "Favorites_Jan1998_CD01.2c.mp3" to "199801_Favorites_CD01.2c.mp3"

Change file 3: "Favorites_Jan1998_CD02.1c.mp3" to "199801_Favorites_CD02.1c.mp3"

and so on.

In other words, I want to strip everything before the CD number and add the string "199801_Favorites_CD"

Thanks

munna_dude · 07-31-2007, 01:27 AM

Quote:

Originally Posted by 6millionbucks

Hello All,

I have found ways to change file names, file extensions, uppercase to lowercase but I cant figure out how to change the prefix of multiple files in a directory using a script. For example:

Change file 1: "Favorites_Jan1998_CD01.1c.mp3" to "199801_Favorites_CD01.1c.mp3"

Change file 2: "Favorites_Jan1998_CD01.2c.mp3" to "199801_Favorites_CD01.1c.mp3"

Change file 3: "Favorites_Jan1998_CD02.1c.mp3" to "199801_Favorites_CD01.1c.mp3"

and so on.

In other words, I want to strip everything before the CD number and add the string "199801_Favorites_CD"

Thanks

may be usefull.

Code:

for f in Favorites_*.mp3 ## ls is unnecesary and will break the script
do
  touch "${Favorites_f%}199801_Favorites_CD01.1c.mp3" ## no external command is necessary
done

cheers
munna

6millionbucks · 07-31-2007, 10:24 AM

Quote:

Originally Posted by munna_dude

may be usefull.

Code:

for f in Favorites_*.mp3 ## ls is unnecesary and will break the script
do
  touch "${Favorites_f%}199801_Favorites_CD01.1c.mp3" ## no external command is necessary
done

cheers
munna

Thanks munna for the reply. It kind of worked (as far as renaming) the first file in the directory and then I realized I had typos in my original post. Ooooppps, sorry. Its suppose to read:

Change file 1: "Favorites_Jan1998_CD01.1c.mp3" to "199801_Favorites_CD01.1c.mp3"

Change file 2: "Favorites_Jan1998_CD01.2c.mp3" to "199801_Favorites_CD01.2c.mp3"

Change file 3: "Favorites_Jan1998_CD02.1c.mp3" to "199801_Favorites_CD02.1c.mp3"

How do I get the script to rename for all the files in the directory. The files should have the same prefix (199801_Favorites_CD) but a different CD and track number (01.1c, 01.2c, 02.1c).

Lastly, the reason I said "kind of worked" is because the original file size was 3 MBs, the renamed file is 0. Why do you think that is?

Thanks again for your help.

pwc101 · 07-31-2007, 10:47 AM

Try this:

Code:

for i in *.mp3; do
   rename Favorites_Jan1998 199801_Favourites $i
done

Or you could do it with a find command, which might be more efficient if you have a huge number of files.

edit: Clearly I have no idea what I'm talking about with respect to touch. Touch won't affect existing files other than to change certain aspects of them (e.g. timestamp etc.). Don't know why they're 0 bytes now. Sorry!

nuying117 · 07-31-2007, 11:50 AM

why dont you use mv command? I dont know why you all use rename or other command

Quote:

for f in `ls`
do
mv $f "198101_${f}"
done

colucix · 07-31-2007, 12:01 PM

Quote:

Originally Posted by pwc101

edit: Clearly I have no idea what I'm talking about with respect to touch. Touch won't affect existing files other than to change certain aspects of them (e.g. timestamp etc.). Don't know why they're 0 bytes now. Sorry!

Very dangerous to suggest some untested code to a newbie! And very dangerous for a newbie to accept some code without testing or seeing man pages if some command are unknown!

Here is the explanation: the touch command update the timestamp of a file to the current time or a desired one (with -t option). The touch command with a non-existent file as argument, simply creates an empty file.
The command

Code:

touch "${Favorites_f%}199801_Favorites_CD01.1c.mp3"

probably was meant to strip a substring from the original file name and replace it with a new one, but as you have seen, this was not the correct way to do. The example with the rename command should work, instead. Cheers.

colucix · 07-31-2007, 12:06 PM

Quote:

for f in `ls`
do
mv $f "198101_${f}"
done

Same as above... dangeroooous! He he he... I look pedantic, I know!

6millionbucks · 07-31-2007, 06:16 PM

Thanks nuying117, pwc101 and colucix.

As far as

Code:

for i in *.mp3; do
   rename Favorites_Jan1998 199801_Favorites $i
done

Nothing happens when I run this.

As for the code

Code:

for f in `ls`
do
mv $f "198101_${f}"
done

It's getting closer to what I'm looking for except it didn't remove the "Jan1998":

"Favorites_Jan1998_CD01.1c.mp3" becomes "199801_Favorites_Jan1998_CD01.1c.mp3"

Still need to drop the "Jan1998" of the final name.

I'm currently digging up info on string replace. I think it would be simpler to replace the string "Favorites_Jan1998" with the string "199801_Favorites".

Would appreciate your help with this approach. Thanks everybody... you guys are great.

6millionbucks · 07-31-2007, 10:24 PM

I've been at this all day... I'm calling it a night but here is what I came up with so far. I found a script on this website that changes "spaces" to "_".

So I figured I would try changing "Favorites_Jan1998" to "199801_Favorites" in the code below.

Code:

for f in *.mp3; do
     file=$(echo $f | tr 'Favorites_Jan1998' '1998_Favorites')
     [ ! -f $file ] && mv "$f" $file
done

Output:

The original file "Favorites_Jan1998_CD01.1c.mp3" becomes "1998_FavorJ9nieesrCD0i.ic.mp3"

Why the strange name? What am I doing wrong?

Help

pwc101 · 08-01-2007, 02:36 AM

tr 'Favorites_Jan1998' '1998_Favorites' - tr doesn't do words, it does individual letters. For words, something like sed might be more appropriate:

Code:

for f in *.mp3; do
     file=$(echo $f | sed 's/Favorites_Jan1998/1998_Favorites/g')
     [ ! -f $file ] && mv "$f" $file
done

pwc101 · 08-01-2007, 02:48 AM

Quote:

Originally Posted by colucix

Very dangerous to suggest some untested code to a newbie!

I didn't suggest the touch code! I had to edit my post as I had written something about touch which was clearly wrong. That's what I was apologising for there

colucix · 08-01-2007, 08:08 AM

Quote:

Originally Posted by pwc101

I didn't suggest the touch code! I had to edit my post as I had written something about touch which was clearly wrong. That's what I was apologising for there

Sorry, pwc101! You make me notice I have quoted the erroneous text. Indeed, it was not you which posted the example with touch. By the way my comment was simply and slightly ironic (I hope this was clear). Cheers

pwc101 · 08-01-2007, 08:12 AM

I knew you were being slightly sarcastic, so I didn't take offence, but I thought I'd point it out in case someone else tried it and I got it in the neck! Got to keep up appearances, you know...

6millionbucks · 08-01-2007, 11:05 AM

Quote:

Originally Posted by pwc101

tr 'Favorites_Jan1998' '1998_Favorites' - tr doesn't do words, it does individual letters. For words, something like sed might be more appropriate:

Code:

for f in *.mp3; do
     file=$(echo $f | sed 's/Favorites_Jan1998/1998_Favorites/g')
     [ ! -f $file ] && mv "$f" $file
done

That did the trick, thanks so much. I'm reading up on sed now. A week ago a didn't know a thing about scripting or programing, and today I still don't but I know I love it.

Thanks pwc101 and everyone else for your help and comments