如何设置 pexpect ssh 会话的列宽？
How do I set the column width of a pexpect ssh session?
我正在编写一个简单的 python 脚本来通过 SSH 连接到 SAN，运行 一组命令。最终，每个命令都将连同时间戳记录到单独的日志中，然后退出。这是因为我们正在连接的设备不支持证书 ssh 连接，并且在其当前固件版本上没有合适的日志记录功能。
我似乎 运行 遇到的问题是创建的 SSH 会话似乎限制为 78 个字符宽。每个命令生成的结果要宽得多——155 个字符。这引起了一堆时髦。
首先，当前状态下的结果更难解析。其次，由于缓冲区明显较小，最终的卷命令将无法正确执行，因为预期启动的 SSH 会话实际上被提示为 "press any key to continue".
如何更改预期会话的列宽？
这是当前代码（可以使用但不完整）：
#!/usr/bin/python
import pexpect
import os
PASS='mypassword'
HOST='1.2.3.4'
LOGIN_COMMAND='ssh manage@'+HOST
CTL_COMMAND='show controller-statistics'
VDISK_COMMAND='show vdisk-statistics'
VOL_COMMAND='show volume-statistics'
VDISK_LOG='vdisk.log'
VOLUME_LOG='volume.log'
CONTROLLER_LOG='volume.log'
DATE=os.system('date +%Y%m%d%H%M%S')
child=pexpect.spawn(LOGIN_COMMAND)
child.setecho(True)
child.logfile = open('FetchSan.log','w+')
child.expect('Password: ')
child.sendline(PASS)
child.expect('# ')
child.sendline(CTL_COMMAND)
print child.before
child.expect('# ')
child.sendline(VDISK_COMMAND)
print child.before
child.expect('# ')
print "Sending "+VOL_COMMAND
child.sendline(VOL_COMMAND)
print child.before
child.expect('# ')
child.sendline('exit')
child.expect(pexpect.EOF)
print child.before
预期输出：
# show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
---------------------------------------------------------------------------------------------------------------------------------------------------------
controller_A 0 45963169 1573.3KB 67 386769785 514179976 6687.8GB 5750.6GB
controller_B 20 45963088 4627.4KB 421 3208370173 587661282 63.9TB 5211.2GB
---------------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
# show vdisk-statistics
Name Serial Number Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
------------------------------------------------------------------------------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0 45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2282.4KB 164 23229435 76509765 5506.7GB 1605.3GB
DATA1 00c0ff1311f3000087d8c44f00000000 2286.5KB 167 23490851 78314374 5519.0GB 1603.8GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0 26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 654.8KB 5 3049980 15317236 1187.3GB 1942.1GB
FRA1 00c0ff13349e000007d9c44f00000000 778.7KB 6 3016569 15234734 1179.3GB 1940.4GB
------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
# show volume-statistics
Name Serial Number Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
-----------------------------------------------------------------------------------------------------------------------------------------------------
CRS_v001 00c0ff13349e0000fdd6c44f01000000 14.8KB 5 239611146 107147564 1321.1GB 110.5GB
DATA1_v001 00c0ff1311f30000d0d8c44f01000000 2402.8KB 218 1701488316 336678620 33.9TB 3184.6GB
DATA2_v001 00c0ff1311f3000040f9ce5701000000 0B 0 921 15 2273.7KB 2114.0KB
DATA_v001 00c0ff1311f30000bdd7c44f01000000 2303.4KB 209 1506883611 250984824 30.0TB 2026.6GB
FRA1_v001 00c0ff13349e00001ed9c44f01000000 709.1KB 28 25123082 161710495 1891.0GB 2230.0GB
FRA_v001 00c0ff13349e00001fd8c44f01000000 793.0KB 34 122052720 245322281 3475.7GB 3410.0GB
-----------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
打印到终端的输出（如前所述，第三条命令不会在其当前状态下执行）：
show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
controller_A 3 45962495 3803.1KB
73 386765821 514137947 6687.8GB
5748.9GB
controller_B 20 45962413 5000.7KB
415 3208317860 587434274 63.9TB
5208.8GB
----------------------------------------------------------------------
Success: Command completed successfully.
Sending show volume-statistics
show vdisk-statistics
Name Serial Number Bytes per second IOPS
Number of Reads Number of Writes Data Read Data Written
----------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0
45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2187.2KB 152
23220764 76411017 5506.3GB 1604.1GB
DATA1 00c0ff1311f3000087d8c44f00000000 2295.2KB 154
23481442 78215540 5518.5GB 1602.6GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0
26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 1829.3KB 14
3049951 15310681 1187.3GB 1941.2GB
FRA1 00c0ff13349e000007d9c44f00000000 1872.8KB 14
3016521 15228157 1179.3GB 1939.5GB
----------------------------------------------------------------------------
Success: Command completed successfully.
Traceback (most recent call last):
File "./fetchSAN.py", line 34, in <module>
child.expect('# ')
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/spawnbase.py", line 321, in expect
timeout, searchwindowsize, async)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/spawnbase.py", line 345, in expect_list
return exp.expect_loop(timeout)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/expect.py", line 107, in expect_loop
return self.timeout(e)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/expect.py", line 70, in timeout
raise TIMEOUT(msg)
pexpect.exceptions.TIMEOUT: Timeout exceeded.
<pexpect.pty_spawn.spawn object at 0x105333910>
command: /usr/bin/ssh
args: ['/usr/bin/ssh', 'manage@10.254.27.49']
buffer (last 100 chars): '-------------------------------------------------------------\r\nPress any key to continue (Q to quit)'
before (last 100 chars): '-------------------------------------------------------------\r\nPress any key to continue (Q to quit)'
after: <class 'pexpect.exceptions.TIMEOUT'>
match: None
match_index: None
exitstatus: None
flag_eof: False
pid: 19519
child_fd: 5
closed: False
timeout: 30
delimiter: <class 'pexpect.exceptions.EOF'>
logfile: <open file 'FetchSan.log', mode 'w+' at 0x1053321e0>
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1
searcher: searcher_re:
0: re.compile("# ")
这是日志中捕获的内容：
Password: mypassword
HP StorageWorks MSA Storage P2000 G3 FC
System Name: Uninitialized Name
System Location:Uninitialized Location
Version:TS230P008
# show controller-statistics
show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
controller_A 3 45962495 3803.1KB
73 386765821 514137947 6687.8GB
5748.9GB
controller_B 20 45962413 5000.7KB
415 3208317860 587434274 63.9TB
5208.8GB
----------------------------------------------------------------------
Success: Command completed successfully.
# show vdisk-statistics
show vdisk-statistics
Name Serial Number Bytes per second IOPS
Number of Reads Number of Writes Data Read Data Written
----------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0
45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2187.2KB 152
23220764 76411017 5506.3GB 1604.1GB
DATA1 00c0ff1311f3000087d8c44f00000000 2295.2KB 154
23481442 78215540 5518.5GB 1602.6GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0
26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 1829.3KB 14
3049951 15310681 1187.3GB 1941.2GB
FRA1 00c0ff13349e000007d9c44f00000000 1872.8KB 14
3016521 15228157 1179.3GB 1939.5GB
----------------------------------------------------------------------------
Success: Command completed successfully.
# show volume-statistics
show volume-statistics
Name Serial Number Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
CRS_v001 00c0ff13349e0000fdd6c44f01000000 11.7KB
5 239609039 107145979 1321.0GB
110.5GB
DATA1_v001 00c0ff1311f30000d0d8c44f01000000 2604.5KB
209 1701459941 336563041 33.9TB
3183.3GB
DATA2_v001 00c0ff1311f3000040f9ce5701000000 0B
0 921 15 2273.7KB
2114.0KB
DATA_v001 00c0ff1311f30000bdd7c44f01000000 2382.8KB
194 1506859273 250871273 30.0TB
2025.4GB
FRA1_v001 00c0ff13349e00001ed9c44f01000000 1923.5KB
31 25123006 161690520 1891.0GB
2229.1GB
FRA_v001 00c0ff13349e00001fd8c44f01000000 2008.5KB
37 122050872 245301514 3475.7GB
3409.1GB
----------------------------------------------------------------------
Press any key to continue (Q to quit)%
作为起点：According to the manual，SAN 有一个禁用寻呼机的命令。请参阅 set cli-parameters pager off 的文档。执行该命令可能就足够了。它也可能有一个命令来设置它用于格式化输出的终端行和列，尽管我找不到一个。
回答您的问题：当 ssh 客户端连接到服务器并请求交互式会话时，它可以选择为会话的服务器端请求 PTY（伪 tty）。当它这样做时，它会通知服务器服务器应该用于 TTY 的行、列和终端类型。您的 SAN 可能会接受 PTY 请求并使用行和列值来格式化其输出。或者它可能不会。
ssh 客户端从 TTY 获取 PTY 请求的行和列作为其标准输入。这是 pexpect 用来与 ssh 通信的 PTY。
this question discusses how to set the terminal size for a pexpect session. Ssh doesn't honor the LINES or COLUMNS environment variables as far as I can tell, so I doubt that would work. However, calling child.setwinsize() 生成 ssh 后应该可以工作：
child = pexpect.spawn(cmd)
child.setwinsize(400,400)
如果您对此有困难，您可以尝试通过在 ssh 之前在本地调用 stty 来设置终端大小：
child=pexpect.spawn('stty rows x cols y; ssh user@host')
最后，您需要确保 ssh 确实为会话请求了 PTY。它在某些情况下默认执行此操作，这应该包括您的方式 运行。但是它有一个命令行选项 -tt 来强制它分配一个 PTY。您可以将该选项添加到 ssh 命令行以确保：
child=pexpect.spawn('ssh -tt user@host')
or
child=pexpect.spawn('stty rows x cols y; ssh -tt user@host')
我正在编写一个简单的 python 脚本来通过 SSH 连接到 SAN，运行 一组命令。最终，每个命令都将连同时间戳记录到单独的日志中，然后退出。这是因为我们正在连接的设备不支持证书 ssh 连接，并且在其当前固件版本上没有合适的日志记录功能。
我似乎 运行 遇到的问题是创建的 SSH 会话似乎限制为 78 个字符宽。每个命令生成的结果要宽得多——155 个字符。这引起了一堆时髦。
首先，当前状态下的结果更难解析。其次，由于缓冲区明显较小，最终的卷命令将无法正确执行，因为预期启动的 SSH 会话实际上被提示为 "press any key to continue".
如何更改预期会话的列宽？
这是当前代码（可以使用但不完整）：
#!/usr/bin/python
import pexpect
import os
PASS='mypassword'
HOST='1.2.3.4'
LOGIN_COMMAND='ssh manage@'+HOST
CTL_COMMAND='show controller-statistics'
VDISK_COMMAND='show vdisk-statistics'
VOL_COMMAND='show volume-statistics'
VDISK_LOG='vdisk.log'
VOLUME_LOG='volume.log'
CONTROLLER_LOG='volume.log'
DATE=os.system('date +%Y%m%d%H%M%S')
child=pexpect.spawn(LOGIN_COMMAND)
child.setecho(True)
child.logfile = open('FetchSan.log','w+')
child.expect('Password: ')
child.sendline(PASS)
child.expect('# ')
child.sendline(CTL_COMMAND)
print child.before
child.expect('# ')
child.sendline(VDISK_COMMAND)
print child.before
child.expect('# ')
print "Sending "+VOL_COMMAND
child.sendline(VOL_COMMAND)
print child.before
child.expect('# ')
child.sendline('exit')
child.expect(pexpect.EOF)
print child.before
预期输出：
# show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
---------------------------------------------------------------------------------------------------------------------------------------------------------
controller_A 0 45963169 1573.3KB 67 386769785 514179976 6687.8GB 5750.6GB
controller_B 20 45963088 4627.4KB 421 3208370173 587661282 63.9TB 5211.2GB
---------------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
# show vdisk-statistics
Name Serial Number Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
------------------------------------------------------------------------------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0 45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2282.4KB 164 23229435 76509765 5506.7GB 1605.3GB
DATA1 00c0ff1311f3000087d8c44f00000000 2286.5KB 167 23490851 78314374 5519.0GB 1603.8GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0 26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 654.8KB 5 3049980 15317236 1187.3GB 1942.1GB
FRA1 00c0ff13349e000007d9c44f00000000 778.7KB 6 3016569 15234734 1179.3GB 1940.4GB
------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
# show volume-statistics
Name Serial Number Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
-----------------------------------------------------------------------------------------------------------------------------------------------------
CRS_v001 00c0ff13349e0000fdd6c44f01000000 14.8KB 5 239611146 107147564 1321.1GB 110.5GB
DATA1_v001 00c0ff1311f30000d0d8c44f01000000 2402.8KB 218 1701488316 336678620 33.9TB 3184.6GB
DATA2_v001 00c0ff1311f3000040f9ce5701000000 0B 0 921 15 2273.7KB 2114.0KB
DATA_v001 00c0ff1311f30000bdd7c44f01000000 2303.4KB 209 1506883611 250984824 30.0TB 2026.6GB
FRA1_v001 00c0ff13349e00001ed9c44f01000000 709.1KB 28 25123082 161710495 1891.0GB 2230.0GB
FRA_v001 00c0ff13349e00001fd8c44f01000000 793.0KB 34 122052720 245322281 3475.7GB 3410.0GB
-----------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
打印到终端的输出（如前所述，第三条命令不会在其当前状态下执行）：
show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
controller_A 3 45962495 3803.1KB
73 386765821 514137947 6687.8GB
5748.9GB
controller_B 20 45962413 5000.7KB
415 3208317860 587434274 63.9TB
5208.8GB
----------------------------------------------------------------------
Success: Command completed successfully.
Sending show volume-statistics
show vdisk-statistics
Name Serial Number Bytes per second IOPS
Number of Reads Number of Writes Data Read Data Written
----------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0
45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2187.2KB 152
23220764 76411017 5506.3GB 1604.1GB
DATA1 00c0ff1311f3000087d8c44f00000000 2295.2KB 154
23481442 78215540 5518.5GB 1602.6GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0
26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 1829.3KB 14
3049951 15310681 1187.3GB 1941.2GB
FRA1 00c0ff13349e000007d9c44f00000000 1872.8KB 14
3016521 15228157 1179.3GB 1939.5GB
----------------------------------------------------------------------------
Success: Command completed successfully.
Traceback (most recent call last):
File "./fetchSAN.py", line 34, in <module>
child.expect('# ')
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/spawnbase.py", line 321, in expect
timeout, searchwindowsize, async)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/spawnbase.py", line 345, in expect_list
return exp.expect_loop(timeout)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/expect.py", line 107, in expect_loop
return self.timeout(e)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/expect.py", line 70, in timeout
raise TIMEOUT(msg)
pexpect.exceptions.TIMEOUT: Timeout exceeded.
<pexpect.pty_spawn.spawn object at 0x105333910>
command: /usr/bin/ssh
args: ['/usr/bin/ssh', 'manage@10.254.27.49']
buffer (last 100 chars): '-------------------------------------------------------------\r\nPress any key to continue (Q to quit)'
before (last 100 chars): '-------------------------------------------------------------\r\nPress any key to continue (Q to quit)'
after: <class 'pexpect.exceptions.TIMEOUT'>
match: None
match_index: None
exitstatus: None
flag_eof: False
pid: 19519
child_fd: 5
closed: False
timeout: 30
delimiter: <class 'pexpect.exceptions.EOF'>
logfile: <open file 'FetchSan.log', mode 'w+' at 0x1053321e0>
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1
searcher: searcher_re:
0: re.compile("# ")
这是日志中捕获的内容：
Password: mypassword
HP StorageWorks MSA Storage P2000 G3 FC
System Name: Uninitialized Name
System Location:Uninitialized Location
Version:TS230P008
# show controller-statistics
show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
controller_A 3 45962495 3803.1KB
73 386765821 514137947 6687.8GB
5748.9GB
controller_B 20 45962413 5000.7KB
415 3208317860 587434274 63.9TB
5208.8GB
----------------------------------------------------------------------
Success: Command completed successfully.
# show vdisk-statistics
show vdisk-statistics
Name Serial Number Bytes per second IOPS
Number of Reads Number of Writes Data Read Data Written
----------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0
45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2187.2KB 152
23220764 76411017 5506.3GB 1604.1GB
DATA1 00c0ff1311f3000087d8c44f00000000 2295.2KB 154
23481442 78215540 5518.5GB 1602.6GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0
26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 1829.3KB 14
3049951 15310681 1187.3GB 1941.2GB
FRA1 00c0ff13349e000007d9c44f00000000 1872.8KB 14
3016521 15228157 1179.3GB 1939.5GB
----------------------------------------------------------------------------
Success: Command completed successfully.
# show volume-statistics
show volume-statistics
Name Serial Number Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
CRS_v001 00c0ff13349e0000fdd6c44f01000000 11.7KB
5 239609039 107145979 1321.0GB
110.5GB
DATA1_v001 00c0ff1311f30000d0d8c44f01000000 2604.5KB
209 1701459941 336563041 33.9TB
3183.3GB
DATA2_v001 00c0ff1311f3000040f9ce5701000000 0B
0 921 15 2273.7KB
2114.0KB
DATA_v001 00c0ff1311f30000bdd7c44f01000000 2382.8KB
194 1506859273 250871273 30.0TB
2025.4GB
FRA1_v001 00c0ff13349e00001ed9c44f01000000 1923.5KB
31 25123006 161690520 1891.0GB
2229.1GB
FRA_v001 00c0ff13349e00001fd8c44f01000000 2008.5KB
37 122050872 245301514 3475.7GB
3409.1GB
----------------------------------------------------------------------
Press any key to continue (Q to quit)%
作为起点：According to the manual，SAN 有一个禁用寻呼机的命令。请参阅 set cli-parameters pager off 的文档。执行该命令可能就足够了。它也可能有一个命令来设置它用于格式化输出的终端行和列，尽管我找不到一个。
回答您的问题：当 ssh 客户端连接到服务器并请求交互式会话时，它可以选择为会话的服务器端请求 PTY（伪 tty）。当它这样做时，它会通知服务器服务器应该用于 TTY 的行、列和终端类型。您的 SAN 可能会接受 PTY 请求并使用行和列值来格式化其输出。或者它可能不会。
ssh 客户端从 TTY 获取 PTY 请求的行和列作为其标准输入。这是 pexpect 用来与 ssh 通信的 PTY。
this question discusses how to set the terminal size for a pexpect session. Ssh doesn't honor the LINES or COLUMNS environment variables as far as I can tell, so I doubt that would work. However, calling child.setwinsize() 生成 ssh 后应该可以工作：
child = pexpect.spawn(cmd)
child.setwinsize(400,400)
如果您对此有困难，您可以尝试通过在 ssh 之前在本地调用 stty 来设置终端大小：
child=pexpect.spawn('stty rows x cols y; ssh user@host')
最后，您需要确保 ssh 确实为会话请求了 PTY。它在某些情况下默认执行此操作，这应该包括您的方式 运行。但是它有一个命令行选项 -tt 来强制它分配一个 PTY。您可以将该选项添加到 ssh 命令行以确保：
child=pexpect.spawn('ssh -tt user@host')
or
child=pexpect.spawn('stty rows x cols y; ssh -tt user@host')