how to delete a sub directory whose name is appended to the end of its parent folder's name

Question

Parent folder contains subdir name appended at the end

Delimiter is underscore _:

a_b_c  (parent folder contains sub directory name at the end)
  |c/ (to be deleted)
  |..
d_f
  |..
  |f/ (to be deleted)
g_h
  |h/ (to be deleted)
  |..

Output should be

a_b_c  (parent folder contains sub directory name at the end)
  |..
d_f
  |..
g_h
  |..

What I have with me is get the subdirectory name

"$PWD" |rev|cut -d"_" -f1|rev  (input: a_b_c output: c)

Not sure how to delete the subdirectory. Help please!

I understood that it should remove all directories one level down, which start with an undescore. Then you have to describe how the directories to be deleted should look like, and which should be left alone? — user1934428, Jan 27 '21 at 17:43

choroba · Accepted Answer · 2021-01-27T16:45:55.533

3

Loop over the directories, use parameter expansion to remove everything before the last underscore:

#! /bin/bash
for dir in * ; do
    last=${dir##*_}
    [[ -d $dir/$last ]] && rmdir "$dir/$last"
done

edited Jan 27 '21 at 16:45

answered Jan 27 '21 at 14:18

choroba

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Hi @choroba where to place this script? I am not sure how to give the directory input – Dinesh Ravi Jan 27 '21 at 14:33
Place it wherever you like, call it from the root of the hierarchy. Or, send the root directory as a parameter and start the script with `cd "$1" || exit 1`. – choroba Jan 27 '21 at 15:04
I placed alongside or in same level to that of dir it needs to be processed. It didn't work – Dinesh Ravi Jan 27 '21 at 15:12
@DineshRavi: How did you run it? How did it fail? – choroba Jan 27 '21 at 15:32
I just copied into test.sh file & placed at same level of the dir a_b_c & executed. It gave no error & flipside it did not delete the c sub folder – Dinesh Ravi Jan 27 '21 at 16:08
@DineshRavi: How exactly did you execute it? – choroba Jan 27 '21 at 16:15
bash test.sh thats it – Dinesh Ravi Jan 27 '21 at 16:16
What is an example of a real path you wanted to delete? – choroba Jan 27 '21 at 16:26
/home/dinesh/auto_car/car/ is the folder which needs to be deleted /home/dinesh/food_fruits_apple/apple/ is the folder which needs to be deleted even edge case /home/dinesh/school/school needs to be deleted – Dinesh Ravi Jan 27 '21 at 16:29
I see. I thought the subdirectory name is `_c`, not just `c`, but you probably used `_` as a drawing character :-( – choroba Jan 27 '21 at 16:40
1

Just remove the `_` after `last=`. – choroba Jan 27 '21 at 16:41
If you want it to operate also on directories without `_` in their name, use `for dir in *`. – choroba Jan 27 '21 at 16:42
1

If the directories aren't empty, use `rm -rf` isntead of `rmdir`. – choroba Jan 27 '21 at 16:43
But list them before you delete them so you don't lose any data. – choroba Jan 27 '21 at 16:45

Raman Sailopal · Answer 2 · 2021-01-27T14:45:38.530

1

while IFS= read -r -d '' dir;
do 
  if test -d "$dir/${dir#*_*_}";
  then 
       echo "rm -Rf $dir/${dir#*_*_}";
       # rm -Rf "$dir/${dir#*_*_}";
  fi;
done <<< "$(find . -type d -regextype posix-extended -regex "^.*[[:alpha:]]{1}_[[:alpha:]]{1}_[[:alpha:]]{1}$" -print0)"

Utilising find to execute a regular expression search for directories only that have the pattern outlined, redirect the output back into a while loop, reading them into a variable dir. We then strip the last character with ${dir#**} before removing the directory path if it exists.

Echo the remove command before removing the comment marker to execute.

edited Jan 27 '21 at 14:45

answered Jan 27 '21 at 14:25

Raman Sailopal

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Utilize the `find` commands `-print0`option to [handle file names containing newlines](http://mywiki.wooledge.org/BashFAQ/020) and to handle them in your while loop change `while read dir` to `while IFS= read -r -d '' dir` – RobC Jan 27 '21 at 14:43
Thanks for input @RobC I've amended the answer with the improvements. – Raman Sailopal Jan 27 '21 at 14:47
@RamanSailopal How to pass the input root directory name to this script? – Dinesh Ravi Jan 27 '21 at 15:00
Replace the . in find for the path – Raman Sailopal Jan 27 '21 at 15:23
Hi I copied above code into test2.sh & placed alongside a_b_c & executed using bash test2.sh. It didn't echo the command. Am I doing it wrong? – Dinesh Ravi Jan 27 '21 at 16:18
Run the find command manually first and make sure that it is listing the directories required. – Raman Sailopal Jan 27 '21 at 16:21

how to delete a sub directory whose name is appended to the end of its parent folder's name

2 Answers2