Replace os.popen4 by subprocess to not mix error messages

and stdout.
This prevent to return "No character boxes found! ..."
returns by ocrupus from stderr instead of '' from stdout.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@35728 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/PortalTransforms/transforms/png_to_text.py

+# -*- coding: utf-8 -*-
 from Products.PortalTransforms.interfaces import itransform
 from Products.PortalTransforms.libtransforms.commandtransform \
     import popentransform
-
+from subprocess import Popen, PIPE
 import os
 import tempfile
 from zope.interface import implements
@@ -13,7 +14,7 @@ class png_to_text(popentransform):
     inputs   = ('image/png',)
     output  = 'text/plain'
     output_encoding = 'utf-8'
-    
+
     __version__ = '2008-10-07.01'
 
     binaryName = "ocrocmd"
@@ -24,29 +25,28 @@ class png_to_text(popentransform):
         # XXX Surcharge from commandtransform, as ocrocmd do not accept 
         # parameters but environnement variable.
         # Surcharging prevent to put the variable in the zope.conf file
-        command = "%s %s" % (self.binary, self.binaryArgs)
+        command = self.binary
+        environment = {'quiet': '1',
+                       'hocr': '0',
+                       'blockwise': '0'}
         if not self.useStdin:
             tmpfile, tmpname = tempfile.mkstemp(text=False) # create tmp
             os.write(tmpfile, data) # write data to tmp using a file descriptor
             os.close(tmpfile)       # close it so the other process can read it
-            command = command % { 'infile' : tmpname } # apply tmp name to command
-
-        cin, couterr = os.popen4('quiet=1 hocr=0 blockwise=0 %s' % command, 'b')
+            popen = Popen([command, tmpname], env=environment, stdout=PIPE)
+            out = popen.communicate()[0]
 
-        if self.useStdin:
-            cin.write(str(data))
-
-        status = cin.close()
-
-        out = self.getData(couterr)
-        couterr.close()
+        else:
+            popen = Popen([command, tmpname], env=environment, stdin=PIPE,
+                                                                   stdout=PIPE)
+            out = popen.communicate(str(data))[0]
 
         if not self.useStdin:
             # remove tmp file
             os.unlink(tmpname)
-                     
-        cache.setData(out)                                                                                                                             
-        return cache       
+
+        cache.setData(out)
+        return cache
 
 def register():
     return png_to_text()