[GRASS-dev] [GRASS GIS] #2326: Command functions in grass.script.core miss a correct error reporting

[GRASS GIS]

#2326: Command functions in grass.script.core miss a correct error reporting
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 Reporter:  wenzeslaus   |       Owner:  grass-dev@…              
     Type:  enhancement  |      Status:  new                      
 Priority:  normal       |   Milestone:  7.1.0                    
Component:  Python       |     Version:  svn-trunk                
 Keywords:  script       |    Platform:  All                      
      Cpu:  Unspecified  |  
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Comment(by glynn):

 Replying to [ticket:2326 wenzeslaus]:

 I missed this issue in my previous reply:

 >
 {{{
 proc.stdin.write(proj_in)
 proc.stdin.close()
 proc.stdin = None
 proj_out, errors = proc.communicate()
 }}}

 You need to use
 {{{
 proj_out, errors = proc.communicate(proj_in)
 }}}

 If you try to .write() the data to stdin, and the child process prints
 progress/error/etc messages as it processes the input, you'll get deadlock
 if the amount of data written to either pipe exceeds the amount which will
 fit in the pipe's buffer.

 The .communicate() method uses either non-blocking I/O (Unix) or threads
 (Windows) in order to consume output as it becomes available, rather than
 waiting until all data has been written to stdin and hoping that the
 pipe's buffer can contain everything written to stdout/stderr in the
 meantime.

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2326#comment:4>
GRASS GIS <http://grass.osgeo.org>