add a "--verbose" option that writes to stderr if it finds anything to omit

Also cleaned up some flakes noticed by pyflakes, and make the scrub() be @classmethod instead of @staticmethod so I could use the class for the verbose output.

caveats:

* there are no unit tests of this patch
* now your logs of your stderr have potentially sensitive information in them
* the implementation of arg parsing is very low-tech; (a *good* way to do arg parsing is the "argparse" module)

bin/pdfparanoia

@@ -13,6 +13,15 @@ if __name__ == "__main__":
     import fileinput
     from StringIO import StringIO
 
+    verbose = False
+    while '--verbose' in sys.argv:
+        verbose = True
+        sys.argv.pop(sys.argv.index('--verbose'))
+
+    while '-v' in sys.argv:
+        verbose = True
+        sys.argv.pop(sys.argv.index('-v'))
+
     import pdfparanoia
 
     # read in all lines
@@ -21,7 +30,7 @@ if __name__ == "__main__":
         content += line
 
     # scrub the pdf to get rid of watermarks
-    output = pdfparanoia.scrub(StringIO(content))
+    output = pdfparanoia.scrub(StringIO(content), verbose=verbose)
 
     # dump to output
     sys.stdout.write(output)

pdfparanoia/core.py

@@ -32,7 +32,7 @@ def find_plugins():
     plugins = [each[1] for each in plugins]
     return plugins
 
-def scrub(obj):
+def scrub(obj, verbose=False):
     """
     Removes watermarks from a pdf and returns the resulting pdf as a string.
     """
@@ -50,7 +50,7 @@ def scrub(obj):
 
     # clean this pdf as much as possible
     for plugin in plugins:
-        content = plugin.scrub(content)
+        content = plugin.scrub(content, verbose=verbose)
 
     return content
 

pdfparanoia/plugin.py

@@ -8,8 +8,8 @@ Defines how plugins work.
 """
 
 class Plugin:
-    @staticmethod
-    def scrub(content):
+    @classmethod
+    def scrub(cls, content, verbose=False):
         """
         Removes watermarks from the given pdf.
         """

pdfparanoia/plugins/aip.py

@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 
+import sys
+
 from copy import copy
 
 from ..parser import parse_content
@@ -15,8 +17,8 @@ class AmericanInstituteOfPhysics(Plugin):
     attached for whatever reason.
     """
 
-    @staticmethod
-    def scrub(content):
+    @classmethod
+    def scrub(cls, content, verbose=False):
         evil_ids = []
 
         # parse the pdf into a pdfminer document
@@ -43,6 +45,9 @@ class AmericanInstituteOfPhysics(Plugin):
                         data = copy(obj.get_data())
 
                         if "Redistribution subject to AIP license or copyright" in data:
+                            if verbose:
+                                sys.stderr.write("%s: Found object with %r; omitting..." % (cls.__name__, data,))
+
                             evil_ids.append(objid)
 
         for objid in evil_ids:

pdfparanoia/plugins/ieee.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 from copy import copy
+import sys
 
 from ..parser import parse_content
 from ..eraser import remove_object_by_id
@@ -13,8 +14,8 @@ class IEEEXplore(Plugin):
 
     """
 
-    @staticmethod
-    def scrub(content):
+    @classmethod
+    def scrub(cls, content, verbose=False):
         evil_ids = []
 
         # parse the pdf into a pdfminer document
@@ -38,6 +39,9 @@ class IEEEXplore(Plugin):
                     data = copy(obj.get_data())
 
                     if "Authorized licensed use limited to: " in data:
+                        if verbose:
+                            sys.stderr.write("%s: Found object with %r; omitting..." % (cls.__name__, data,))
+
                         evil_ids.append(objid)
 
         for objid in evil_ids:

pdfparanoia/plugins/jstor.py

@@ -2,9 +2,10 @@
 
 from copy import copy
 
+import sys
+
 from ..parser import parse_content
 from ..eraser import (
-    remove_object_by_id,
     replace_object_with,
 )
 from ..plugin import Plugin
@@ -32,8 +33,8 @@ class JSTOR(Plugin):
         "This content downloaded  on",
     ]
 
-    @staticmethod
-    def scrub(content):
+    @classmethod
+    def scrub(cls, content, verbose=False):
         replacements = []
 
         # jstor has certain watermarks only on the first page
@@ -54,8 +55,6 @@ class JSTOR(Plugin):
 
             if hasattr(obj, "attrs"):
                 if obj.attrs.has_key("Filter") and str(obj.attrs["Filter"]) == "/FlateDecode":
-                    length = obj.attrs["Length"]
-                    rawdata = copy(obj.rawdata)
                     data = copy(obj.get_data())
 
                     # make sure all of the requirements are in there
@@ -82,6 +81,10 @@ class JSTOR(Plugin):
                         if page_id == 0 and "/F2 11 Tf\n" in better_content:
                             startpos = better_content.rfind("/F2 11 Tf\n")
                             endpos = better_content.find("Tf\n", startpos+5)
+
+                            if verbose:
+                                sys.stderr.write("%s: Found object with %r; omitting..." % (cls.__name__, better_content[startpos:endpos],))
+
                             better_content = better_content[0:startpos] + better_content[endpos:]
 
                         replacements.append([objid, better_content])

pdfparanoia/plugins/spie.py

@@ -1,9 +1,9 @@
 # -*- coding: utf-8 -*-
 
 from copy import copy
+import sys
 
 from ..parser import parse_content
-from ..eraser import remove_object_by_id
 from ..plugin import Plugin
 
 class SPIE(Plugin):
@@ -18,8 +18,8 @@ class SPIE(Plugin):
 
     """
 
-    @staticmethod
-    def scrub(content):
+    @classmethod
+    def scrub(cls, content, verbose=False):
         evil_ids = []
 
         # parse the pdf into a pdfminer document
@@ -41,6 +41,8 @@ class SPIE(Plugin):
                     data = copy(obj.get_data())
 
                     if "Downloaded From:" in data:
+                        if verbose:
+                            sys.stderr.write("%s: found object with %r; omitting..." % (cls.__name__, data))
                         evil_ids.append(objid)
 
         for objid in evil_ids: