Using the passwd command from within a shell script

Question

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 prompting me for the new password. My code is below.

adduser $1
passwd $1
$2
$2

Answer 1

from " man 1 passwd<\/code> ":

   --stdin
          This option is used to indicate that passwd should read the new
          password from standard input, which can be a pipe.

Answer 2

The only solution works on Ubuntu 12.04:

echo -e "new_password\nnew_password" | (passwd user)

Answer 3

现在，您可以使用以下命令：

echo "user:pass" | chpasswd

Answer 4

Read the wise words from:

• <\/li><\/ul>

  I quote:

  passwd(1) does not read from standard input. This is intentional. It is for your protection. Passwords were never intended to be put into programs, or generated by programs. They were intended to be entered only by the fingers of an actual human being, with a functional brain, and never, ever written down anywhere.

   Though I still wouldn't recommend it.
   Even if you think your box is safe; it's something you should really<\/strong> get in the habit of avoiding at all cost (yes, even the cost of doing a bit more trouble getting the job done).
  

Answer 5

For those who need to 'run as root' remotely through a script logging into a user account in the sudoers file, I found an evil horrible hack, that is no doubt very insecure:

sshpass -p 'userpass' ssh -T -p port user@server << EOSSH
sudo -S su - << RROOT
userpass
echo ""
echo "*** Got Root ***"
echo ""
#[root commands go here]
useradd -m newuser
echo "newuser:newpass" | chpasswd
RROOT
EOSSH

Answer 6

Here-document<\/em> works if your passwd<\/code> doesn't support --stdin<\/code> and you don't want to (or can't) use chpasswd<\/code> for some reason.

#!/usr/bin/env bash

username="user"
password="pass"

passwd ${username} << EOD
${password}
${password}
EOD

Answer 7

你可以使用 chpasswd

echo $1:$2 | chpasswd<\/code>

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Answer 8

Tested this on a CentOS VMWare image that I keep around for this sort of thing. Note that you probably want to avoid putting passwords as command-line arguments, because anybody on the entire machine can read them out of 'ps -ef'.

user="$1"
password="$2"
adduser $user
echo $password | passwd --stdin $user

Answer 9

Sometimes it is useful to set a password which nobody knows. This seems to work:

tr -dc A-Za-z0-9 < /dev/urandom | head -c44 | passwd --stdin $user

Answer 10

I stumbled upon the same problem and for some reason the --stdin<\/code> option was not available on the version of passwd<\/code> I was using (shipped in Ubuntu 14.04).

echo "<user>:<password>" | chpasswd

Answer 11

This is the definitive answer for a teradata node admin.

SMP007-1
SMP007-2
SMP007-3

Answer 12

For me on Raspbian it works only this way (old password added):

#!/usr/bin/env bash

username="pi"
password="Szevasz123"
new_ps="Szevasz1234"

passwd ${username} << EOD
${password}
${new_ps}
${new_ps}
EOD

Answer 13

echo 'yourPassword' | sudo -S yourCommand

<\/blockquote>

Answer 14

Have you looked at the -p<\/code> option of adduser<\/code> (which AFAIK is just another name for useradd<\/code> )? You may also want to look at the -P<\/code> option of luseradd<\/code> which takes a plaintext password, but I don't know if luseradd<\/code> is a standard command (it may be part of SE Linux or perhaps just an oddity of Fedora).

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Answer 15

You can use the expect<\/code> utility<\/a> to drive all programs that read from a tty (as opposed to stdin, which is what passwd does). Expect comes with ready to run examples for all sorts of interactive problems, like passwd entry.

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