如何防止 pexpect 回显密码？

Question

默认情况下，pexpect.spawn() 不会输出任何内容。但是当我指定 logfile=sys.stdout 时，它也会回显密码（例如 ssh）。那么，如何在不回显密码的情况下查看与 spawned 进程的实时交互（就像 Expect（Tcl 扩展名）一样）？

pexepct 示例：

# cat expect.py
import pexpect, sys

logfile = sys.stdout if len(sys.argv) == 2 else None

ssh = pexpect.spawn('ssh foo@localhost', logfile=logfile)
ssh.delaybeforesend = 1
ssh.expect('assword:')
ssh.sendline('123456')

ssh.expect('\r\n\$')
ssh.sendline('exit')
ssh.expect(pexpect.EOF)
ssh.wait()
# python expect.py                 <-- no output
# python expect.py stdout
foo@localhost's password: 123456   <-- the password is visible
Last login: Tue Mar 22 10:32:49 2016 from localhost
$ exit
exit
Connection to localhost closed.
#

预期例子：

# cat ssh.exp
spawn ssh foo@localhost
expect assword:
send "123456\r"
expect {$}
send "exit\r"
expect eof
wait
# expect ssh.exp
spawn ssh foo@localhost
foo@localhost's password:          <-- the password is invisible
Last login: Tue Mar 22 10:45:03 2016 from localhost
$ exit
Connection to localhost closed.
#

Answer 1

只是为了让问题得到解答。归功于 Thomas K。有关更多详细信息，请参阅他在问题下的评论。

[STEP 101] # cat foo.py
#!/usr/bin/env python3

import pexpect, sys

spawn = pexpect.spawnu if sys.version_info[0] >= 3 else pexpect.spawn
ssh = spawn('ssh -t foo@localhost bash --noprofile --norc')
ssh.logfile_read = sys.stdout

ssh.expect('assword:')
ssh.sendline('123456')

ssh.expect('bash-[.0-9]+[$#]')
ssh.sendline('exit')
ssh.expect(pexpect.EOF)
ssh.wait()
[STEP 102] #
[STEP 103] # python2 foo.py
foo@localhost's password:
bash-5.1$ exit
exit
Connection to localhost closed.
[STEP 104] #
[STEP 105] # python3 foo.py
foo@localhost's password:
bash-5.1$ exit
exit
Connection to localhost closed.
[STEP 106] #

如何防止 pexpect 回显密码？

How to prevent pexpect from echoing the password?

expect

python-2.x

pexpect