Search for file formats + options - bash

Question

I was fiddling around with bash last month and am trying to create a script.
I want the script to search through the folders for files with some kind of extension defined by the argument -e. The folders are defined without -option. The output is 2 columns where in the first it prints the found files, and in the second the respective folders.
Is this the most efficient and/or flexible way to go?
I also can't manage to let the -l command work. Any idea what's wrong? When I enter -name \${CHAR}*, it simply doesn't work. Also, how can I make it recognize a range being used? With an if-function looking for the "-" character or something?
I think I managed to mount a block device, but how can I add the path as a parameter so it can be used as a folder? Setting a number as a var doesn't work, it tells me it doesn't recognize the command.
For some reason the 'no recursion' tag works, but the 'no numbers' doesn't. I have no idea why this would be different.
When using the 'no recursion' (nn) and 'no numbers' (nr) tags I use a long tag --tag for the arguments. Is it possible to use only 1 -tag? This is possible with get opts, but then I can't manage to use the other tags after the get opts has been used. Someone a solution?
Finally, is it possible, when finding 2 files with the same file name, instead of printing the file twice, can it just show the file once. But for every file with the same name keep a white space, so it can still show all the folders in the second column?
#!/bin/bash
#FUNCTIONS
#Error
#Also written to stderr
err() {
echo 1>&2;
echo "Error, not enough arguments" 1>&2;
echo "Usage: $0 [-e <file extension>] [<folder>]";
echo "Please enter the argument -e and at least 1 folder.";
echo "More: Please chek Help by using -h or --help.";
echo 1>&2;
exit
}
#Help
help() {
echo
echo "--- Help ---"
echo
echo "This script will look for file extentions in 1 or more directories. The output shows the found files with the according folder where it's located."
echo
echo "Argument -e <ext> is required."
echo "Other arguments the to-look-trough folders."
echo
echo "These are also usable options:"
echo "-h or --help shows this."
echo "-l <character> looks for files starting with the character."
echo "-l <character1>-<character2> does the same, but looks trough a range of characters."
echo "-b <block-device> mounts a partition to /mnt and let it search through."
echo "--nn (no numbers) makes sure there are no numbers in the file name."
echo "--nr (no recursion) doesn't look trough subdirectories."
echo "-r of –-err <file> writes the errors (f.e. corrupted directory) to <file>."
echo "-s <word> searches the word through the files and only shows the files having that word."
echo
exit
}
#VARS
#execute getopt
OPTS=$(getopt -o e:hl:b:r:s: -l "help,nn,nr,err" -n "FileExtensionScript" -- "$#");
#Bad arguments
if [ $? -ne 0 ];
then
err;
exit
fi
#Rearrange arguments
eval set -- "$OPTS";
#echo "AFTER SET -- \$OPTS: $#";
while true; do
case "$1" in
-e)
shift;
if [ -n "$1" ]; then
EXT=$1;
shift;
fi
;;
-h|--help)
shift;
help;
;;
-l)
shift;
if [ -n "$1" ]; then
CHAR=$1;
shift;
fi
;;
-b)
shift;
if [ -n "$1" ]; then
sudo mkdir /mnt/$1;
sudo echo -e "/dev/$1 /mnt/$1 vfat defaults 0 0 " >> /etc/fstab;
sudo mount -a;
999=/mnt/$1;
shift;
fi
;;
--nn)
shift;
NONUM=" ! -name '*[0-9]*'";
;;
--nr)
shift;
NOREC="-maxdepth 1";
;;
-f|--err)
shift;
if [ -n "$1" ]; then
ERROR="| 2>filename | tee -a $1";
shift;
fi
;;
-s)
shift;
if [ -n "$1" ]; then
SEARCH="-name '*$1*'";
shift;
fi
;;
--)
shift;
break;
;;
esac
done
#No folder or arguments given
if [ $# -lt 1 ];
then
err;
exit
fi
#Debug
echo "Folder argumenten: $#" >2;
echo \# $# >2;
#Create arrays with found files and according folders
FILES=( $(find $# $NOREC $SEARCH $NONUM -name \*.${EXT} $ERROR | rev | cut -d/ -f 1 | rev) )
FOLDERS=( $(find $# $NOREC $SEARCH $NONUM -name \*.${EXT} $ERROR | rev | cut -d/ -f 1 --complement | rev) )
#Show arrays in 2 columns
for ((i = 0; i <= ${#FILES[#]}; i++));
do
printf '%s %s\n' "${FILES[i]}" "${FOLDERS[i]}"
done | column -t | sort -k1 #Make columns cleaner + sort on filename
I am not native English speaker and am hoping to get some tips to finish my script :) Thanks in advance!