Bash IFS ('\n'): Problems with file name detection through find command and for loop

Question

#!/bin/bash

IFS='\n' 
declare -i count=0

AX=$(find *.iso -maxdepth 1 -type f) # Rather use AX="$(find *.iso -maxdepth 1 -type f"?
# A="${AX%x}" < Could I use this when applying "" to $() in AX? But it should already include newlines like this way. edit: I don't need the trailing newlines fix.

for iso in "$AX"
 do
  echo "Use "$iso"? [Y/N]?" # Outputs ALL files, IFS has no force somehow
  read choiceoffile
  shopt -s nocasematch
  case $choiceoffile in
  y ) echo "Using selected file.";;
  * ) continue;;
  esac
  # some sort of processing
done

Is the command substitution done right? The variable does not work with the IFS \n in the for loop, I don't get why this occurs.

for loop is supposed to process filenames with blank space by processing the output of find line by line (thats why I use the IFS \n).

I don't understand the question here. Can you explain more? Why are you looping over .iso files but then using find to get the .wbfs files? Would it not be easier to just loop over both and count the iso files and use an array for the wbfs files and then just use array offset indexing to get the count you want? case $image in *.iso) count+=1;; *.wbfs) files+=("$image");; esac and then "${files[@]:$count}"? — Etan Reisner
– Etan Reisner, Commented Jul 8, 2015 at 13:31
I wasn't fast enough in editing. It are all $iso in the plain text of my script. — Max Hopfgartner
– Max Hopfgartner, Commented Jul 8, 2015 at 13:33
The question body outside your code should have some additional explanation of what the problem is. Is there an exception, or is the output / result simply not what you expected? If not, why? — Palu Macil
– Palu Macil, Commented Jul 8, 2015 at 13:33
What about this code isn't working? If the code isn't accurate to what you have locally or are trying to do then edit it and fix it. And please, as Palu Macil said more clearly, give us more description about what you are trying to do and what is (and isn't) happening with this code. — Etan Reisner
– Etan Reisner, Commented Jul 8, 2015 at 13:37
What is the purpose of that find command? You are getting a count of every iso file from the loop and then using find and limiting its output to exactly that same count? — Etan Reisner
– Etan Reisner, Commented Jul 8, 2015 at 13:38

Jahid · Accepted Answer · 2015-07-08 14:09:57Z

2

The variable does not work with the IFS \n in the for loop, I don't get why this occurs.

IFS='\n' doesn't set IFS to newline, it sets IFS to a literal string \n. If you want to set IFS to newline, use:

IFS=$'\n'

answered Jul 8, 2015 at 14:09

Jahid

22.6k10 gold badges97 silver badges114 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Max Hopfgartner Over a year ago

Thanks, that was the problem besides the quotation.

Etan Reisner · Accepted Answer · 2015-07-08 14:25:05Z

1

I don't see a need for find or the first loop here at all.

Does this do what you want?

for iso in *.iso
 do
  echo "Use $iso? [Y/N]?"
  read choiceoffile
  shopt -s nocasematch
  case $choiceoffile in
  y ) echo "Using selected file.";;
  * ) continue;;
  esac
  # some sort of processing
done

I also removed the useless n) case as the default case handles that just fine.

answered Jul 8, 2015 at 14:25

Etan Reisner

81.7k8 gold badges120 silver badges154 bronze badges

Comments

Marki555 · Accepted Answer · 2015-07-09 06:56:56Z

1

I fixed it by now. I have thrown away the quotation of the variable in the for loop, fixed the declaration of IFS in the beginning and removed the unnecessary piping.
This should be a good solution to the white space problem
Thanks, now I can insert this into my working script. Why did I kept the quotes?

#!/bin/bash

IFS=$'\n'   

AX=$(find *.wbfs -maxdepth 1 -type f )  

for wbfs in $AX  
 do  
  echo "Use "$wbfs"? [Y/N]?"  
  read choiceoffile  
  shopt -s nocasematch  
    case $choiceoffile in  
      y ) echo "Using selected file.";;  
      * ) continue;;  
    esac  
   # some sort of processing  
done

edited Jul 9, 2015 at 6:56

Marki555

6,9803 gold badges43 silver badges60 bronze badges

answered Jul 8, 2015 at 14:27

Max Hopfgartner

495 bronze badges

1 Comment

Marki555 Over a year ago

This can also fail if you by mistake happen to have newline in some filename

Collectives™ on Stack Overflow

Bash IFS ('\n'): Problems with file name detection through find command and for loop

3 Answers 3

1 Comment

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related