Separate folders into subfolders according to numbering in bash - bash

Question

I have the following directory tree:
1_loc
2_buzdfg
4_foodga
5_bardfg
6_loc
8_buzass
9_foossd
12_bardaf
There may be numbers missing in the folder ordering.
I want to separate these folders into subfolders according to their numbers, so that all folders with a number smaller than 6 (before the second _loc folder) would go to folder1 and all folders with a number equal or greater than 6 with go to folder2.
I can solve the problem very easily using the mouse, of course, but I wanted a suggestion of how to do this automatically from the terminal.
Any ideas?

Answer 1

while read -r line; do
# Regex match the beginning of the string for a character between 1 and 5 - change this as you'd please to any regex
FOLDERNUMBER=""
[[ "$line" ~= "^[1-5]" ]] && FOLDERNUMBER="1" || FOLDERNUMBER="2"
# So FOLDERPATH = "./folder1", if FOLDERNUMBER=1
FOLDERPATH="./folder$FOLDERNUMBER"
# Check folder exists, if not create it
[[ ! -d "$FOLDERPATH" ]] && mkdir "$FOLDERPATH"
# Finally, move the file to FOLDERPATH
mv "$line" "$FOLDERPATH/$(basename $line)"
done < <(find . -type f)
# This iterates through each line of the command in the brackets - in this case, each file path from the `find` command.

Answer 2

I think the solution is to loop through the files and check the number before the first _.
Firstly, let's check how to get the number before _:
$ d="1_loc_b"
$ echo "${d%%_*}"
1
OK, so this works. Then, let's loop:
for file in *
do
echo "$file"
(( ${file%%_*} > 5)) && echo "moving to dir2/" || echo "moving to dir1/"
done

Answer 3

Suppose folder1 and folder2 exists in the same directory, I will do it like this:
for d in *_*; do # to avoid folder1 and folder2
# check if the first field seperated by _ is less than 5
if ((`echo $d | cut -d"_" -f1` < 6)); then
mv $d folder1/$d;
else
mv $d folder2/$d;
fi;
done
(more about cut)

Answer 4

You can go to the current directory and run these simple commands:
mv {1,2,3,4}_* folder1/
mv {5,6,7,8}_* folder2/
This assumes no other files/directory starting with these prefixes (i.e. 1-8).

Answer 5

Another pure bash, parameter-expansion solution:-
#!/bin/bash
# 'find' returns folders having a '_' in their names, the flag -print0 option to
# preserve special characters in names.
# the folders are names as './1_folder', './2_folder', bash magic is done
# to remove those special characters.
# '-v' flag in 'mv' for verbose action
while IFS= read -r -d '' folder; do
folderName="${folder%_*}" # To strip the characters after the '_'
finalName="${folderName##*/}" # To strip the everything before '/'
((finalName > 5)) && mv -v "$folder" folder1 || mv -v "$folder" folder2
done < <(find . -maxdepth 1 -mindepth 1 -name "*_*" -type d -print0)

Answer 6

You can create the a script with the following code and when you run it, the folders will be moved as desired..
#seperate the folders into 2 folders
#this is a generic solution for any folder that start with a number
#!/bin/bash
for file in *
do
prefix=`echo $file | awk 'BEGIN{FS="_"};{print $1}'`
if [[ $prefix != ?(-)+([0-9]) ]]
then continue
fi
if [ $prefix -le 4 ]
then mv "$file" folder1
elif [ $prefix -ge 5 ]
then mv "$file" folder2
fi
done