ddwrt

adduser.sh

user=user
password=`openssl passwd -1 -salt xyz your-password-here`

cp /etc/passwd /tmp/passwd.bak

echo "${user}:${password}:1000:1000:User,,,:/tmp/${user}:/bin/sh" >> /etc/passwd
mkdir /tmp/${user}
chmod 1000:1000 /tmp/user

redirect.sh

#!/bin/sh -x 

# -x shows all commands

exec > script.log 2>&1

echo "do this"
touch that
echo do more

# + echo 'do this'
# do this
# + touch that
# + echo 'do' more
# do more