chpasswd 8 System Management Commands chpasswd update passwords in batch mode chpasswd options chpasswd 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. passwd1 , newusers8 , useradd8 .