chpasswd 8 System Management Commands chpasswd update passwords in batch mode chpasswd options The chpasswd command reads a list of user name and password pairs from standard input and uses this information to update a group of existing users. Each line is of the format: user_name:password By default the supplied password must be in clear-text. Default encryption algorithm is DES. Also the password age will be updated, if present. This command is intended to be used in a large system environment where many accounts are created at a single time. The options which apply to the chpasswd command are: -e, --encrypted Supplied passwords are in encrypted form. -h, --help Display help message and exit. -m, --md5 Use MD5 encryption instead of DES when the supplied passwords are not encrypted. Remember to set permissions or umask to prevent readability of unencrypted files by other users. chpasswd does not use PAM to update the passwords. Thus, It only updates the passwords from the /etc/passwd and /etc/shadow databases, and does not support the various checks provided by PAM modules. passwd1 , newusers8 , useradd8 .