Bash: Recreate recursively sub-directories - bash

Question

I've got a lot of files in a lot of sub-directories.
I would like to perform some task on them and return the result in a new file, but in an output directory which has the exact same sub-directories as the input.
I try already this:
#!/bin/bash
########################################################
# $1 = "../benchmarks/k"
# $2 = Output Folder;
# $3 = Path to access the solver
InputFolder=$1;
OutputFolder=$2;
Solver=$3
mkdir -p $2;
########################################
#
# Send the command on the cluster
# to run the solver on the instancee.
#
########################################
solveInstance() {
instance=$1;
# $3 $instance > $2/$i.out
}
########################################
#
# Loop on benchmarks folders recursively
#
########################################
loop_folder_recurse() {
for i in "$1"/*;
do
if [ -d "$i" ]; then
echo "dir: $i"
mkdir -p "$2/$i";
loop_folder_recurse "$i"
elif [ -f "$i" ]; then
solveInstance "$i"
fi
done
}
########################################
#
# Main of the Bash script.
#
########################################
echo "Dir: $1";
loop_folder_recurse $1
########################################################
The problem is my line mkdir -p "$2/$i";. $2 is the name of a directory that we create at the beginning, so there is no problem. But in $i, it can be an absolute path and in that case it wants to create all the sub-directories to arrive to the file : Not possible. Or it can contain .. and same kind of problem appear...
I don't know exactly how to fix this bug :/ I try some things with sed but I did not succeed :/

Answer 1

The easiest way is to use find:
for i in `find $1 -type d` # Finds all the subfolders and loop.
do
mkdir ${i/$1/$2} # Replaces the root with the new root and creates the dir.
done
In such a way you recreate the folder structure of $1 in $2. You can even avoid the loop if you use sed to replace the old folder path with the new.