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Re: how to run shell command like "<<EOT .... EOT"

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  Re: how to run shell command like "<<EOT .... EOT" 叶佑群 <ye.youqun@eisoo.com> - 2012-09-29 08:34 +0800

#30443 — Re: how to run shell command like "<<EOT .... EOT"

于 2012-9-28 16:16, Kushal Kumaran 写道:
> On Fri, Sep 28, 2012 at 1:15 PM, 叶佑群<ye.youqun@eisoo.com>  wrote:
>> Hi, all,
>>
>>      I have the shell command like this:
>>
>> sfdisk -uM /dev/sdb<<  EOT
>> ,1000,83
>> ,,83
>> EOT
>>
>>
>>      I have tried subprocess.Popen, pexpect.spawn and os.popen, but none of
>> these works, but when I type this shell command in shell, it is works fine.
>> I wonder how to emulate this type of behavior in python , and if someone can
>> figure out the reason why?
>>
>>      The sample code of subprocess.Popen is:
>>
>>      command = ["sfdisk", "-uM",  target, "<<EOT", "\r\n",
>>                  ",", 1000, ",", "83", "\r\n",
>>                  ",", ",", "83", "\r\n", "EOT", "\r\n"]
>>
>>      pobj = subprocess.Popen (command, bufsize=1, \
>>                          stderr=subprocess.PIPE, stdout=subprocess.PIPE)
>>
>>      res = pobj.stderr.readline ()
>>      if res is not None and pobj.returncode != 0:
>>          observer.ShowProgress (u"对设备 %s 分区失败！" % target)
>>          return False
>>
> The "<<EOT" syntax (called a here-document) just provides input to the
> command.  If you use the communicate method, you can provide input as
> an argument:
>
> command = ["sfdisk", "-uM",  target ]
> instructions = """
> ,1000,83
> ,,83
> """
> pobj = subprocess.Popen(command, stdin=subprocess.PIPE,
> stdout=subprocess.PIPE, stderr=subprocess.PIPE)
> (output, errors) = pobj.communicate(instructions)
If I want to read the output line by line and not put all output to 
memory buffer in one time, how to write the code?
>>      and pexpect code is:
>>
>>      child = pexpect.spawn ("sfdisk -uM /dev/sdb<<EOT")
>>      child.sendline (....)
>>      child.sendline (....)
>>      child.sendline (....)
>>
>>      and os.popen like this:
>>
>>          os.popen ("sfdisk -uM /dev/sdb<<EOT\n,1000,83\n,,83\nEOT\n")
>>
>>      I tried "\r\n", and it doesn't work either.
>>

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