chpasswd(8) -- Linux man page
NAMEchpasswd - update password file in batch
DESCRIPTIONchpasswd reads a file of user name and password pairs from standard input and uses this information to update a group of existing users. Without the -e switch, the passwords are expected to be cleartext. With the -e switch, the passwords are expected to be in encrypted form. Each line is of the format
The named user must exist. The supplied password will be encrypted as necessary, and the password age updated, if present.
CAVEATSThe input file must be protected if it contains unencrypted passwords.
SEE ALSOpasswd(1), newusers(8), useradd(8)
AUTHORJulianne Frances Haugh (email@example.com)