[Python] Pexpect.spawn object Child calls read () when a timeout exception is triggered

Design Intent: Initialize the Spawn object once, execute SSH post, a series of Cmds. Most of the time online via SSH [email protected] cmd method, so that I need to call through for:

def ssh_commands (ip,user,passwd,command): try:ssh_pc = Pexpect.spawn (' SSH%[email protected]%s%s '% (user,ip,c Ommand), Timeout=5,logfile=logfile) ... r=ssh_pc.read () print R except TIMEOUT,EOF:SSH_PC.C Lose () ... for cmd in Cmds:ssh_commands (ip,user,passwd,cmd)

However, the Spawn object is generated for each for, so my method is:

def ssh_commands (ip,user,passwd,commands): try:ssh_pc = Pexpect.spawn (' SSH%[email protected]%s '% (user,ip), TI meout=5,logfile=logfile) ... for command in Commands:ssh_pc.expect (' # ') Ssh_pc.sendli NE (command) r=ssh_pc.read () print R except Timeout,eof:ssh_pc.close () ... Ssh_commands (IP,USER,PASSWD,CMDS)

My code is as follows:

Import pexpectimport sysdef ssh_commands (ip,user,passwd,commands):     ip= STR (IP)     user=str (user)     passwd=str (passwd)       #logfile =file ('%s_%s '  %  (ip,user), ' W ')     logfile=sys.stdout     ssh_pc = pexpect.spawn (' ssh %[email protected]%s '  %  (USER,IP), Timeout=5,logfile=logfile)     try:                 match_tag = ssh_pc.expect ([' continue connecting  (yes/no)? ', ' Password: '],timeout=3 '     if match_tag==0:         print  ' # ' *30        ssh_pc.sendline (' yes ')         ssh_pc.expect (' Password: ')          ssh_pc.sendline (PASSWD)         elif match_tag==1:         print  ' = ' *30        ssh_pc.sendline (passwd)          for cmd in commands:         ssh_pc.expect ([' # ', Pexpect. Timeout,pexpect. EOF])         ssh_pc.sendline (cmd)     ssh_pc.expect ([' # ', Pexpect. Timeout,pexpect. EOF])     ssh_pc.close     #ssh_pc. Sendline (' exit ')          print ssh_pc.read ()     except pexpect. eof:          print  ' sub process abort  Unfortinately '     ssh_pc.close    except pexpect. timeout:        print  ' EXpect patterns failed '     ssh_pc.closessh_commands (' 172.172.1.1 ', ' root ', ' Fortinet ', [' uname -a ', ' hostname '])

Operation Result:

[email protected] ' s password: ==============================
Fortinet

Welcome to Ubuntu 12.04.4 LTS (gnu/linux 3.5.0-23-generic x86_64)

* documentation:https://help.ubuntu.com/

System information as of Tue Oct 11:50:25 CST 2014

System load:0.08 Users logged In:2
Usage of/: 12.4% of 28.81GB IP address for eth0:172.172.1.1
Memory usage:5% IP address for eth1:10.1.1.1
Swap usage:0% IP address for eth2:10.16.1.2
processes:218

Graph this data and manage the system at:
https://landscape.canonical.com/

175 packages can be updated.
118 updates are security updates.

New release ' 14.04.1 LTS ' available.
Run ' Do-release-upgrade ' to upgrade to it.

You have new mail.
Last Login:tue Oct-11:05:45 from 172.172.4.1
[Email protected]:~# uname-a
Uname-a
Linux dev-1-a 3.5.0-23-generic #35 ~precise1-ubuntu SMP Fri Jan 17:13:26 UTC x86_64 x86_64 x86_64 gnu/linux
[Email protected]:~# hostname
Hostname
Dev-1-a

[email protected]:~# expect patterns failed here matches to Pexpect. Timeout branch. On-line search of a lot of information, but also read the program written by others, they are in the initialization of the object, the CMD added to the pexpect.spawn command parameters, namely:

SSH_PC = Pexpect.spawn (' ssh%[email protected]%s%s '% (user,ip,cmd), timeout=5,logfile=logfile), I've tried this, and can really circumvent read () Throwing an exception and then putting the entire ssh_commands function into a for loop can also be implemented by passing a list type of CMDS. But this is equivalent to initializing one Spawn class object at a time. And I, I want to initialize a Spawn class object, through expect and Sendline Loop, issued a list type of CMDS.

However, when I uncomment the following line, the timeout exception disappears.

Ssh_pc.sendline (' exit ')

The Code of implementation passed is as follows:

Import pexpectimport sysdef ssh_commands (ip,user,passwd,commands):     ip= STR (IP)     user=str (user)     passwd=str (passwd)       #logfile =file ('%s_%s '  %  (ip,user), ' W ')     logfile=sys.stdout     ssh_pc = pexpect.spawn (' ssh %[email protected]%s '  %  (USER,IP), Timeout=5,logfile=logfile)     try:                 match_tag = ssh_pc.expect ([' continue connecting  (yes/no)? ', ' Password: '],timeout=3 '     if match_tag==0:         print  ' # ' *30        ssh_pc.sendline (' yes ')         ssh_pc.expect (' Password: ')          ssh_pc.sendline (PASSWD)         elif match_tag==1:         print  ' = ' *30        ssh_pc.sendline (passwd)          for cmd in commands:         ssh_pc.expect ([' # ', Pexpect. Timeout,pexpect. EOF])         ssh_pc.sendline (cmd)     ssh_pc.expect ([' # ', Pexpect. Timeout,pexpect. EOF])     ssh_pc.close    ssh_pc.sendline (' exit ')          print ssh_pc.read ()     except pexpect. eof:          print  ' sub process abort  Unfortinately '     ssh_pc.close    except pexpect. timeout:        print  ' exPect patterns failed '     ssh_pc.closessh_commands (' 172.172.1.1 ', ' root ', ' Fortinet ', [' uname -a ', ' hostname '])

Execution Result:

[email protected] ' s password: ==============================
Fortinet

Welcome to Ubuntu 12.04.4 LTS (gnu/linux 3.5.0-23-generic x86_64)

* documentation:https://help.ubuntu.com/

System information as of Tue Oct 12:50:53 CST 2014

System load:0.0 Users logged In:2
Usage of/: 12.4% of 28.81GB IP address for eth0:172.172.1.1
Memory usage:5% IP address for eth1:10.1.1.1
Swap usage:0% IP address for eth2:10.16.1.2
processes:218

Graph this data and manage the system at:
https://landscape.canonical.com/

175 packages can be updated.
118 updates are security updates.

New release ' 14.04.1 LTS ' available.
Run ' Do-release-upgrade ' to upgrade to it.

You have new mail.
Last Login:tue Oct-11:50:25 from 172.22.4.7
[Email protected]:~# uname-a
Uname-a
Linux dev-1-a 3.5.0-23-generic #35 ~precise1-ubuntu SMP Fri Jan 17:13:26 UTC x86_64 x86_64 x86_64 gnu/linux
[Email protected]:~# hostname
Exit
Hostname
Dev-1-a
[Email protected]:~# exit
Logout
Connection to 172.172.1.1 closed.
Hostname
Dev-1-a
[Email protected]:~# exit
Logout
Connection to 172.172.1.1 closed.

Do not understand a problem, I have ssh_pc.read () before the execution of Ssh_pc.close (), why must send another ssh_pc.sendline (' exit ') to circumvent the exception timeout. Please understand the great God pointing. Thank you.

[Python] Pexpect.spawn object Child calls read () when a timeout exception is triggered