How do I change password remotely using ssh?
I tried 'plink ... "echo -e 'adf\nadf' | passwd". But it doesn't work. However such command doesn't work in normal terminal. Is there any suitable batch command?

The problem solved using "expect" command.

I don't understand what you mean.

Do you have an example?

I need to remotely run passwd command and automatically enter and retype password as a user could do manually. Or remotely change password somehow different way.

#passwd
...
Enter password: newpass
Re-type password: newppass
Password changed.

Yes, I understand.

But what command do you execute?

I downloaded "expect" program. This program can reply predefined phrases to expected queries using special script. To connect trhough SSH I use plink program - command line version of PuTTY.

The script:

#change_password host curpass newpass

set host [lindex $argv 0]
set curpass [lindex $argv 1]
set newpass [lindex $argv 2]

spawn plink $host

expect "login as:"
send "root\r"
expect "password:"
send "$curpass\r"

expect {
    "Access denied" "exit 1"
}

expect ":~#"
send "passwd\r"
expect "Enter new password:"
send "$newpass\r"
expect "Re-enter new password:"
send "$newpass\r"
expect ":~#"
send "exit\r"
exit 0

Ok, thanks.

Now, I have understand.