>     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

>     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.

>>      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)

>>      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.

>>      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)

>>      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.

>> On Fri, Sep 28, 2012 at 1:15 PM, 叶佑群<ye.you...@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)

> I tried this, but it is still not work.

>>>> 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)
>> I tried this, but it is still not work.

> What do you mean by "not work"?

> - If you get an exception, copy the entire traceback into an email

> - If you do not get an exception, print out the value of the "errors"
> variable to see why the command failed.  You can also check
> pobj.returncode for the exit status of the subprocess.

> A possibility is that you have to replace "sfdisk" with the full path
> to the binary, if it cannot be located on the PATH.  So you will
> replace it with "/usr/sbin/sfdisk", or "/sbin/sfdisk", or wherever the
> file actually is.

> <from your other email>
>> 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?
> You can read line by line by calling pobj.stdout.readline() and
> pobj.stderr.readline().  You can send input to the process by calling
> pobj.stdin.write().  If you manage this interaction "by hand", you
> should not call communicate().  Also, you should be aware of the
> problem mentioned in the subprocess documentation:

> "Use communicate() rather than .stdin.write, .stdout.read or
> .stderr.read to avoid deadlocks due to any of the other OS pipe
> buffers filling up and blocking the child process."

> Is there any reason why you need to read line-by-line?  You could use
> communicate(), and then call stdout.splitlines() to get a list of
> lines, if that's all you need.