telnet session

[eight02645999]

hi
i am using a telnet session to simulate an authentication mechanism
USER = "user"
PASSWORD = "password"
try:
telnet = telnetlib.Telnet(HOST)
telnet.set_debuglevel(5)
telnet.read_until("login: ")
telnet.write(USER + "\n")
telnet.read_until("Password: ")
telnet.write(PASSWORD + "\n")
except:
print "failed to telnet"
else:
try:
telnet.write("ls\n")
except:
print "cannot ls"
else:
telnet.write("exit\n")
print telnet.read_all()


When i purposely input a wrong password, it "hangs" at the login prompt
waiting for
login and Password. The host i am telnetting to is a unix server.
How can i "exit" this login prompt if the user keys in wrong password
in my script?

 

[Paul Rubin]

When i purposely input a wrong password, it "hangs" at the login prompt
waiting for
login and Password. The host i am telnetting to is a unix server.
How can i "exit" this login prompt if the user keys in wrong password
in my script?

It looks to me like after you send the wrong password, you send "ls"
without checking that you got back another login prompt. Then the
program hangs because both ends are waiting for input.

Whatever your actual application is, try to avoid doing it this way.

 

[Eddie Corns]

hi
i am using a telnet session to simulate an authentication mechanism
USER = "user"
PASSWORD = "password"
try:
telnet = telnetlib.Telnet(HOST)
telnet.set_debuglevel(5)
telnet.read_until("login: ")
telnet.write(USER + "\n")
telnet.read_until("Password: ")
telnet.write(PASSWORD + "\n")
except:
print "failed to telnet"
else:
try:
telnet.write("ls\n")
except:
print "cannot ls"
else:
telnet.write("exit\n")
print telnet.read_all()

When i purposely input a wrong password, it "hangs" at the login prompt
waiting for
login and Password. The host i am telnetting to is a unix server.
How can i "exit" this login prompt if the user keys in wrong password
in my script?

Either do an explicit read_until() for the prompt and fail if it times out or
use expect() to see whether you saw "Password:" or prompt. If you absolutely
don't know what the prompt might be I suppose you could do another
read_until("Password:") and if it times out then assume you got through.