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Re: improving performance of writing into a pipe

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From Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date Mon, 18 Feb 2013 15:21:53 +0000
Subject Re: improving performance of writing into a pipe
To mikprog@gmail.com
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On 18 February 2013 15:12,  <mikprog@gmail.com> wrote:
> Hi guys,
>
> on an embedded linux system (BeagleBoard) I am writing data coming from bluetooth dongle into a pipe.
> The function is the following one:
>
>
> def write_to_pipe(line):
>
>     # next line ensures that bytes like '0x09' are not translated into '\t' for
>     #example, and they are sent as such
>     hexbytes = "\\x" + "\\x".join([hex(ord(c))[2:].zfill(2) for c in line])
>     wrap = ["echo -en '", "' > /tmp/mypipe"]
>     msg = hexbytes.join(wrap)
>     print "DBG: sending: ", msg
>
>     try:
>         os.popen( msg )
>     except:
>         print "Error: write_to_pipe has failed!"
>
>
> Now I typically receive 4 bytes from the bluetooth dongle and that is fine.
> However when I receive many more than that it seems that the writing into the pipe is too slow.
>
> Is there any clever/obvious way to improve the code above?
> (I am quite sure there is to be honest).

Can you not open the pipe file directly in Python code? e.g.

fout = open('/tmp/mypipe', 'w')
fout.write(data)

I guess that this would be more efficient than using os.popen to run echo.


Oscar

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Thread

improving performance of writing into a pipe mikprog@gmail.com - 2013-02-18 07:12 -0800
  Re: improving performance of writing into a pipe Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-02-18 15:21 +0000
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-18 08:31 -0800
      Re: improving performance of writing into a pipe Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2013-02-18 17:49 +0100
        Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-18 09:00 -0800
          Re: improving performance of writing into a pipe Michael Torrie <torriem@gmail.com> - 2013-02-18 11:12 -0700
            Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 01:24 -0800
              Re: improving performance of writing into a pipe Peter Otten <__peter__@web.de> - 2013-02-19 10:55 +0100
                Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 02:27 -0800
                Re: improving performance of writing into a pipe Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-02-19 11:15 +0000
                Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 02:27 -0800
              Re: improving performance of writing into a pipe Michael Torrie <torriem@gmail.com> - 2013-02-19 10:47 -0700
                Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-20 09:54 -0800
                Re: improving performance of writing into a pipe John Gordon <gordon@panix.com> - 2013-02-20 18:39 +0000
                Re: improving performance of writing into a pipe Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-02-20 22:05 +0000
                Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-20 09:54 -0800
            Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 01:24 -0800
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-18 08:31 -0800
  Re: improving performance of writing into a pipe Serhiy Storchaka <storchaka@gmail.com> - 2013-02-18 21:29 +0200
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 04:10 -0800
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 04:10 -0800
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 05:39 -0800
      Re: improving performance of writing into a pipe Peter Otten <__peter__@web.de> - 2013-02-19 14:57 +0100
        Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 06:38 -0800
        Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 06:38 -0800
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 05:39 -0800

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