BASH - parse a config file and create users - sample code.

gistfile1.txt

#!/bin/bash

SFTP_USERS="./sftp_users.txt"
cat ${SFTP_USERS} | while IFS='' read -r LINE || [[ -n "$LINE" ]]
do
  ID=`echo $LINE|cut -d: -f1`
  PASSWORD=`echo $LINE|cut -d: -f2`
  NEWUID=`echo $LINE|cut -d: -f3`
  NEWGID=`echo $LINE|cut -d: -f4`
  if ! id -u ${ID} > /dev/null 2>&1; then
    echo Adding ${ID}
    echo UID is ${NEWUID}
    echo GID is ${NEWGID}
    groupadd --gid " "${NEWGID} ${ID}
    useradd --inactive -1 --comment "service account" --create-home --gid ${NEWGID} --uid ${NEWUID} ${ID}
    echo Adding /incoming/${ID} directories and setting ${ID} password
    echo ${ID}:${PASSWORD} | chpasswd
    mkdir -p /incoming/${ID}/input
    mkdir -p /incoming/${ID}/archived
    mkdir -p /incoming/${ID}/output
    mkdir -p /incoming/${ID}/error
    mkdir -p /incoming/${ID}/processed
    chown -R ${ID}:${ID} /incoming/${ID}/*
  else
    echo ${ID} exists, continuing
    ### Remove id's, uncomment for testing
    #   echo Removing ${ID}
    #   rm -fr /incoming/${ID}
    #   userdel --remove ${ID}
    ###
  fi
done