[SOLVED] How do handle multi word files in a 'for' loop?

sofasurfer · 08-02-2021, 09:16 PM

I know how to use parentheses in a ffmpeg command to increase volume on a multi word filename..

Code:

 $ ffmpeg -i "file.mp3" -filter:a "volume=4" "new file".mp3

But when it is inside of a loop where do I put the parentheses? Or do I have to edit all the filenames?

Code:

 $ for f in *.mp3; do   ffmpeg -i $f -filter:a "volume=4.5" louder/$f; done

I can't get it to read the names without failing.

Michael Uplawski · 08-03-2021, 01:16 AM

Wrong:

Code:

#!/bin/bash

one="One Two One Two"
two="13 kleine Brötchen"
three="Homer Simpson"

for n in $one $two $three
do
  echo "$n"
done

Right:

Code:

#!/bin/bash

one="One Two One Two"
two="13 kleine Brötchen"
three="Homer Simpson"

for n in "$one" "$two" "$three"
do
  echo "$n"
done

PSE consider editing the topic of this thread: Multi-word filenames appears only in the text of the initial post.

pan64 · 08-03-2021, 01:46 AM

It is all about quoting, not parenthesis.
I would suggest you to use shellcheck to analyze your script. It can definitely help you to handle "multi word filenames".
you can try something like this:

Code:

filelist=(*.mp3)
for n in "${filelist[@]}"
do
    echo ffmpeg -i "$n" ....
done

MadeInGermany · 08-03-2021, 07:06 AM

Quote:

Originally Posted by sofasurfer

...

Code:

 $ for f in *.mp3; do   ffmpeg -i $f -filter:a "volume=4.5" louder/$f; done

I can't get it to read the names without failing.

The generated filenames by the *.mp3 are okay.
But in command arguments you must have $variables in quotes.

Code:

 $ for f in *.mp3; do   ffmpeg -i "$f" -filter:a "volume=4.5" "louder/$f"; done

or

Code:

 $ for f in *.mp3; do   ffmpeg -i "$f" -filter:a "volume=4.5" louder/"$f"; done

sofasurfer · 08-04-2021, 05:33 PM

Thanks for this info. And I really like shellcheck.com. Haven't figure it all out yet but I see how it will be a big help.