A script to easily "docker exec" into a running Docker container

docker-shell

#!/bin/bash
# easily "docker exec" into a running Docker container
# latest version: https://gist.github.com/ljm42/2b3bfd8ff886015bbce8

# for unRAID, place this script on your flash drive as /boot/custom/docker-shell
# then add this to your go script (without the leading pound sign):
# cp /boot/custom/docker-shell /usr/local/bin

CONTAINERS=`docker ps | awk 'NR==1 {offset=index($0,"NAMES")};NR>1{print substr($0,offset)}' | sort -f | tr "\n" " "`

echo
echo "Choose a Docker container:"
i=1
for container in $CONTAINERS
do
 echo "$((i++)) : $container"
done

read MYCHOICE
CHOSEN=`echo $CONTAINERS | cut -d' ' -f$MYCHOICE 2>/dev/null`

if [ "$CHOSEN" = "" ]; then
  echo Invalid option
  exit
fi

# try running bash, if exit code 126 then try running sh
for SHELL in bash sh
do
  clear
  echo " "
  echo -e '\E[30;42m'"\033[5m    $CHOSEN - $SHELL   \033[0m"
  echo  " "
  tput sgr0
  docker exec -it $CHOSEN $SHELL
  if [ $? -ne 126 ]; then
    break
  fi
done

Maybe I'am wrong, but if the container has only sh and not additionally bash, this script wont work.
I get an error and the execution ist stopped.

Is is an "php:8.4.18-fpm-alpine3.23" image and alpine does not have bash (without explicit installation). (only sh)

docker-playground-php-fpm-1 - bash

OCI runtime exec failed: exec failed: unable to start container process: exec: "bash": executable file not found in $PATH
# 

Is there a way to safely detect available shell in container?