I\'m writing a shell script to automatically add a new user and update their password. I don\'t know how to get passwd to read from the shell script instead of interactively
I stumbled upon the same problem and for some reason the --stdin option was not available on the version of passwd I was using (shipped in Ubuntu 14.04).
If any of you happen to experience the same issue, you can work it around as I did, by using the chpasswd command like this: