8 files changed, 453 insertions, 256 deletions
diff --git a/gr-blocks/grc/blocks_file_source.xml b/gr-blocks/grc/blocks_file_source.xml
index 1f09e95168..e8ebd98706 100644
--- a/gr-blocks/grc/blocks_file_source.xml
+++ b/gr-blocks/grc/blocks_file_source.xml
@@ -9,7 +9,7 @@
 	<key>blocks_file_source</key>
 	<import>from gnuradio import blocks</import>
 	<import>import pmt</import>
-	<make>blocks.file_source($type.size*$vlen, $file, $repeat)
+	<make>blocks.file_source($type.size*$vlen, $file, $repeat, $offset, $length)
 self.$(id).set_begin_tag($begin_tag)</make>
 	<callback>open($file, $repeat)</callback>
     <callback>self.$(id).set_begin_tag($begin_tag)</callback>
@@ -76,6 +76,18 @@ self.$(id).set_begin_tag($begin_tag)</make>
 		<value>pmt.PMT_NIL</value>
 		<type>raw</type>
 	</param>
+	<param>
+		<name>Offset</name>
+		<key>offset</key>
+		<value>0</value>
+		<type>int</type>
+	</param>
+	<param>
+		<name>Length</name>
+		<key>length</key>
+		<value>0</value>
+		<type>int</type>
+	</param>
 	<check>$vlen &gt; 0</check>
 	<source>
 		<name>out</name>
diff --git a/gr-blocks/include/gnuradio/blocks/file_source.h b/gr-blocks/include/gnuradio/blocks/file_source.h
index c8138339fd..cd73c97d02 100644
--- a/gr-blocks/include/gnuradio/blocks/file_source.h
+++ b/gr-blocks/include/gnuradio/blocks/file_source.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2012 Free Software Foundation, Inc.
+ * Copyright 2012, 2018 Free Software Foundation, Inc.
  *
  * This file is part of GNU Radio
  *
@@ -46,32 +46,41 @@ namespace gr {
        * Opens \p filename as a source of items into a flowgraph. The
        * data is expected to be in binary format, item after item. The
        * \p itemsize of the block determines the conversion from bits
-       * to items.
+       * to items. The first \p offset items (default 0) will be
+       * skipped.
        *
        * If \p repeat is turned on, the file will repeat the file after
        * it's reached the end.
        *
-       * \param itemsize	the size of each item in the file, in bytes
-       * \param filename	name of the file to source from
-       * \param repeat	repeat file from start
+       * If \p len is non-zero, only items [offset, offset+len) will
+       * be produced.
+       *
+       * \param itemsize        the size of each item in the file, in bytes
+       * \param filename        name of the file to source from
+       * \param repeat  repeat file from start
+       * \param offset  begin this many items into file
+       * \param len     produce only items [offset, offset+len)
        */
-      static sptr make(size_t itemsize, const char *filename, bool repeat = false);
+      static sptr make(size_t itemsize, const char *filename, bool repeat = false,
+                       size_t offset = 0, size_t len = 0);
 
       /*!
        * \brief seek file to \p seek_point relative to \p whence
        *
-       * \param seek_point	sample offset in file
-       * \param whence	one of SEEK_SET, SEEK_CUR, SEEK_END (man fseek)
+       * \param seek_point      sample offset in file
+       * \param whence  one of SEEK_SET, SEEK_CUR, SEEK_END (man fseek)
        */
       virtual bool seek(long seek_point, int whence) = 0;
 
       /*!
        * \brief Opens a new file.
        *
-       * \param filename	name of the file to source from
-       * \param repeat	repeat file from start
+       * \param filename        name of the file to source from
+       * \param repeat  repeat file from start
+       * \param offset  begin this many items into file
+       * \param len     produce only items [offset, offset+len)
        */
-      virtual void open(const char *filename, bool repeat) = 0;
+      virtual void open(const char *filename, bool repeat, size_t offset = 0, size_t len = 0) = 0;
 
       /*!
        * \brief Close the file handle.
diff --git a/gr-blocks/lib/file_source_impl.cc b/gr-blocks/lib/file_source_impl.cc
index c077c74fd9..6f4f8fde26 100644
--- a/gr-blocks/lib/file_source_impl.cc
+++ b/gr-blocks/lib/file_source_impl.cc
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2012 Free Software Foundation, Inc.
+ * Copyright 2012, 2018 Free Software Foundation, Inc.
  *
  * This file is part of GNU Radio
  *
@@ -39,35 +39,38 @@
 #include <io.h>
 #endif
 #ifdef O_BINARY
-#define	OUR_O_BINARY O_BINARY
+#define OUR_O_BINARY O_BINARY
 #else
-#define	OUR_O_BINARY 0
+#define OUR_O_BINARY 0
 #endif
 // should be handled via configure
 #ifdef O_LARGEFILE
-#define	OUR_O_LARGEFILE	O_LARGEFILE
+#define OUR_O_LARGEFILE O_LARGEFILE
 #else
-#define	OUR_O_LARGEFILE 0
+#define OUR_O_LARGEFILE 0
 #endif
 
 namespace gr {
   namespace blocks {
 
-    file_source::sptr file_source::make(size_t itemsize, const char *filename, bool repeat)
+    file_source::sptr file_source::make(size_t itemsize, const char *filename, bool repeat,
+                                        size_t start_offset_items, size_t length_items)
     {
       return gnuradio::get_initial_sptr
-	(new file_source_impl(itemsize, filename, repeat));
+        (new file_source_impl(itemsize, filename, repeat, start_offset_items, length_items));
     }
 
-    file_source_impl::file_source_impl(size_t itemsize, const char *filename, bool repeat)
+    file_source_impl::file_source_impl(size_t itemsize, const char *filename, bool repeat,
+                                       size_t start_offset_items, size_t length_items)
       : sync_block("file_source",
-		      io_signature::make(0, 0, 0),
-		      io_signature::make(1, 1, itemsize)),
-	d_itemsize(itemsize), d_fp(0), d_new_fp(0), d_repeat(repeat),
-	d_updated(false), d_file_begin(true), d_repeat_cnt(0),
-       d_add_begin_tag(pmt::PMT_NIL)
+                   io_signature::make(0, 0, 0),
+                   io_signature::make(1, 1, itemsize)),
+        d_itemsize(itemsize),
+        d_start_offset_items(start_offset_items), d_length_items(length_items),
+        d_fp(0), d_new_fp(0), d_repeat(repeat), d_updated(false),
+        d_file_begin(true), d_repeat_cnt(0), d_add_begin_tag(pmt::PMT_NIL)
     {
-      open(filename, repeat);
+      open(filename, repeat, start_offset_items, length_items);
       do_update();
 
       std::stringstream str;
@@ -86,12 +89,35 @@ namespace gr {
     bool
     file_source_impl::seek(long seek_point, int whence)
     {
-      return fseek((FILE*)d_fp, seek_point *d_itemsize, whence) == 0;
+      seek_point += d_start_offset_items;
+
+      switch(whence) {
+      case SEEK_SET:
+        break;
+      case SEEK_CUR:
+        seek_point += (d_length_items - d_items_remaining);
+        break;
+      case SEEK_END:
+        seek_point = d_length_items - seek_point;
+        break;
+      default:
+        GR_LOG_WARN(d_logger, "bad seek mode");
+        return 0;
+      }
+
+      if ((seek_point < (long)d_start_offset_items)
+          || (seek_point > (long)(d_start_offset_items+d_length_items-1))) {
+        GR_LOG_WARN(d_logger, "bad seek point");
+        return 0;
+      }
+
+      return fseek((FILE*)d_fp, seek_point * d_itemsize, SEEK_SET) == 0;
     }
 
 
     void
-    file_source_impl::open(const char *filename, bool repeat)
+    file_source_impl::open(const char *filename, bool repeat,
+                           size_t start_offset_items, size_t length_items)
     {
       // obtain exclusive access for duration of this function
       gr::thread::scoped_lock lock(fp_mutex);
@@ -100,33 +126,61 @@ namespace gr {
 
       // we use "open" to use to the O_LARGEFILE flag
       if((fd = ::open(filename, O_RDONLY | OUR_O_LARGEFILE | OUR_O_BINARY)) < 0) {
-	perror(filename);
-	throw std::runtime_error("can't open file");
+        GR_LOG_ERROR(d_logger, boost::format("%s: %s") % filename % strerror(errno));
+        throw std::runtime_error("can't open file");
       }
 
       if(d_new_fp) {
-	fclose(d_new_fp);
-	d_new_fp = 0;
+        fclose(d_new_fp);
+        d_new_fp = 0;
       }
 
       if((d_new_fp = fdopen (fd, "rb")) == NULL) {
-	perror(filename);
-	::close(fd);	// don't leak file descriptor if fdopen fails
-	throw std::runtime_error("can't open file");
+        GR_LOG_ERROR(d_logger, boost::format("%s: %s") % filename % strerror(errno));
+        ::close(fd);    // don't leak file descriptor if fdopen fails
+        throw std::runtime_error("can't open file");
       }
 
       //Check to ensure the file will be consumed according to item size
       fseek(d_new_fp, 0, SEEK_END);
       int file_size = ftell(d_new_fp);
-      rewind (d_new_fp);
 
-      //Warn the user if part of the file will not be consumed.
-      if(file_size % d_itemsize){
-        GR_LOG_WARN(d_logger, "WARNING: File will not be fully consumed with the current output type");
+      // Make sure there will be at least one item available
+      if ((file_size / d_itemsize) < (start_offset_items+1)) {
+        if (start_offset_items) {
+          GR_LOG_WARN(d_logger, "file is too small for start offset");
+        }
+        else {
+          GR_LOG_WARN(d_logger, "file is too small");
+        }
+        fclose(d_new_fp);
+        throw std::runtime_error("file is too small");
+      }
+
+      size_t items_available = (file_size / d_itemsize - start_offset_items);
+
+      // If length is not specified, use the remainder of the file. Check alignment at end.
+      if (length_items == 0) {
+        length_items = items_available;
+        if (file_size % d_itemsize){
+          GR_LOG_WARN(d_logger, "file size is not a multiple of item size");
+        }
+      }
+
+      // Check specified length. Warn and use available items instead of throwing an exception.
+      if (length_items > items_available) {
+        length_items = items_available;
+        GR_LOG_WARN(d_logger, "file too short, will read fewer than requested items");
       }
 
+      // Rewind to start offset
+      fseek(d_new_fp, start_offset_items * d_itemsize, SEEK_SET);
+
       d_updated = true;
       d_repeat = repeat;
+      d_start_offset_items = start_offset_items;
+      d_length_items = length_items;
+      d_items_remaining = length_items;
     }
 
     void
@@ -136,8 +190,8 @@ namespace gr {
       gr::thread::scoped_lock lock(fp_mutex);
 
       if(d_new_fp != NULL) {
-	fclose(d_new_fp);
-	d_new_fp = NULL;
+        fclose(d_new_fp);
+        d_new_fp = NULL;
       }
       d_updated = true;
     }
@@ -146,15 +200,15 @@ namespace gr {
     file_source_impl::do_update()
     {
       if(d_updated) {
-	gr::thread::scoped_lock lock(fp_mutex); // hold while in scope
+        gr::thread::scoped_lock lock(fp_mutex); // hold while in scope
 
-	if(d_fp)
-	  fclose(d_fp);
+        if(d_fp)
+          fclose(d_fp);
 
-	d_fp = d_new_fp;    // install new file pointer
-	d_new_fp = 0;
-	d_updated = false;
-       d_file_begin = true;
+        d_fp = d_new_fp;    // install new file pointer
+        d_new_fp = 0;
+        d_updated = false;
+        d_file_begin = true;
       }
     }
 
@@ -166,60 +220,62 @@ namespace gr {
 
     int
     file_source_impl::work(int noutput_items,
-			   gr_vector_const_void_star &input_items,
-			   gr_vector_void_star &output_items)
+                           gr_vector_const_void_star &input_items,
+                           gr_vector_void_star &output_items)
     {
       char *o = (char*)output_items[0];
-      int i;
       int size = noutput_items;
 
       do_update();       // update d_fp is reqd
       if(d_fp == NULL)
-	throw std::runtime_error("work with file not open");
+        throw std::runtime_error("work with file not open");
 
       gr::thread::scoped_lock lock(fp_mutex); // hold for the rest of this function
 
+      // No items remaining - all done
+      if (d_items_remaining == 0)
+        return WORK_DONE;
+
       while(size) {
+
         // Add stream tag whenever the file starts again
         if (d_file_begin && d_add_begin_tag != pmt::PMT_NIL) {
-          add_item_tag(0, nitems_written(0) + noutput_items - size, d_add_begin_tag, pmt::from_long(d_repeat_cnt), _id);
+          add_item_tag(0, nitems_written(0) + noutput_items - size,
+                       d_add_begin_tag, pmt::from_long(d_repeat_cnt), _id);
           d_file_begin = false;
         }
 
-	i = fread(o, d_itemsize, size, (FILE*)d_fp);
-
-	size -= i;
-	o += i * d_itemsize;
-
-	if(size == 0)		// done
-	  break;
-
-	if(i > 0)			// short read, try again
-	  continue;
-
-	// We got a zero from fread.  This is either EOF or error.  In
-	// any event, if we're in repeat mode, seek back to the beginning
-	// of the file and try again, else break
-	if(!d_repeat)
-	  break;
-
-	if(fseek ((FILE *) d_fp, 0, SEEK_SET) == -1) {
-	  fprintf(stderr, "[%s] fseek failed\n", __FILE__);
-	  exit(-1);
-	}
-        if (d_add_begin_tag != pmt::PMT_NIL) {
-          d_file_begin = true;
-          d_repeat_cnt++;
+        size_t nitems_to_read = std::min((size_t)size, d_items_remaining);
+
+        // Since the bounds of the file are known, unexpected nitems is an error
+        if (nitems_to_read != fread(o, d_itemsize, nitems_to_read, (FILE*)d_fp))
+          throw std::runtime_error("fread error");
+
+        size -= nitems_to_read;
+        d_items_remaining -= nitems_to_read;
+        o += nitems_to_read * d_itemsize;
+
+        // Ran out of items ("EOF")
+        if (d_items_remaining == 0) {
+
+          // Repeat: rewind and request tag
+          if (d_repeat) {
+            fseek(d_fp, d_start_offset_items * d_itemsize, SEEK_SET);
+            d_items_remaining = d_length_items;
+            if (d_add_begin_tag != pmt::PMT_NIL) {
+              d_file_begin = true;
+              d_repeat_cnt++;
+            }
+          }
+
+          // No repeat: return
+          else {
+            break;
+          }
         }
       }
 
-      if(size > 0) {	     		// EOF or error
-	if(size == noutput_items)       // we didn't read anything; say we're done
-	  return -1;
-	return noutput_items - size;	// else return partial result
-      }
-
-      return noutput_items;
+      return (noutput_items - size);
     }
 
   } /* namespace blocks */
diff --git a/gr-blocks/lib/file_source_impl.h b/gr-blocks/lib/file_source_impl.h
index 19f393fc1d..6de3fc0d16 100644
--- a/gr-blocks/lib/file_source_impl.h
+++ b/gr-blocks/lib/file_source_impl.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2012 Free Software Foundation, Inc.
+ * Copyright 2012, 2018 Free Software Foundation, Inc.
  *
  * This file is part of GNU Radio
  *
@@ -33,6 +33,9 @@ namespace gr {
     {
     private:
       size_t d_itemsize;
+      size_t d_start_offset_items;
+      size_t d_length_items;
+      size_t d_items_remaining;
       FILE *d_fp;
       FILE *d_new_fp;
       bool d_repeat;
@@ -47,16 +50,17 @@ namespace gr {
       void do_update();
 
     public:
-      file_source_impl(size_t itemsize, const char *filename, bool repeat);
+      file_source_impl(size_t itemsize, const char *filename, bool repeat,
+                       size_t offset, size_t len);
       ~file_source_impl();
 
       bool seek(long seek_point, int whence);
-      void open(const char *filename, bool repeat);
+      void open(const char *filename, bool repeat, size_t offset, size_t len);
       void close();
 
       int work(int noutput_items,
-	       gr_vector_const_void_star &input_items,
-	       gr_vector_void_star &output_items);
+               gr_vector_const_void_star &input_items,
+               gr_vector_void_star &output_items);
 
       void set_begin_tag(pmt::pmt_t val);
     };
diff --git a/gr-blocks/python/blocks/qa_file_descriptor_source_sink.py b/gr-blocks/python/blocks/qa_file_descriptor_source_sink.py
new file mode 100644
index 0000000000..c84a82d59f
--- /dev/null
+++ b/gr-blocks/python/blocks/qa_file_descriptor_source_sink.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+#
+# Copyright 2018 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+from gnuradio import gr, gr_unittest, blocks
+import os
+import tempfile
+import pmt
+
+class test_file_descriptor_source_sink(gr_unittest.TestCase):
+
+    def setUp (self):
+        os.environ['GR_CONF_CONTROLPORT_ON'] = 'False'
+        self.tb = gr.top_block ()
+
+    def tearDown (self):
+        self.tb = None
+
+    def test_file_descriptor(self):
+        src_data = range(1000)
+        expected_result = range(1000)
+
+        snk2 = blocks.vector_sink_f()
+
+        with tempfile.NamedTemporaryFile() as temp:
+            fhandle0 = open(temp.name, "wb")
+            fd0 = fhandle0.fileno()
+
+            src = blocks.vector_source_f(src_data)
+            snk = blocks.file_descriptor_sink(gr.sizeof_float, fd0)
+
+            self.tb.connect(src, snk)
+            self.tb.run()
+            os.fsync(fd0)
+            fhandle0.close()
+
+            fhandle1 = open(temp.name, "rb")
+            fd1 = fhandle1.fileno()
+            src2 = blocks.file_descriptor_source(gr.sizeof_float, fd1, False)
+
+            self.tb.disconnect(src, snk)
+            self.tb.connect(src2, snk2)
+            self.tb.run()
+            os.fsync(fd1)
+            fhandle1.close()
+
+        result_data = snk2.data()
+        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
+        self.assertEqual(len(snk2.tags()), 0)
+
+if __name__ == '__main__':
+    gr_unittest.run(test_file_descriptor_source_sink, "test_file_descriptor_source_sink.xml")
diff --git a/gr-blocks/python/blocks/qa_file_sink.py b/gr-blocks/python/blocks/qa_file_sink.py
new file mode 100644
index 0000000000..a7296183ef
--- /dev/null
+++ b/gr-blocks/python/blocks/qa_file_sink.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+#
+# Copyright 2018 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+from gnuradio import gr, gr_unittest, blocks
+import os
+import tempfile
+import pmt
+import array
+
+class test_file_sink(gr_unittest.TestCase):
+
+    def setUp (self):
+        os.environ['GR_CONF_CONTROLPORT_ON'] = 'False'
+        self.tb = gr.top_block ()
+
+    def tearDown (self):
+        self.tb = None
+
+    def test_file_sink(self):
+        data = range(1000)
+        expected_result = data
+
+        with tempfile.NamedTemporaryFile() as temp:
+            src = blocks.vector_source_f(data)
+            snk = blocks.file_sink(gr.sizeof_float, temp.name)
+            snk.set_unbuffered(True)
+            self.tb.connect(src, snk)
+            self.tb.run()
+
+            # Check file length (float: 4 * nsamples)
+            st = os.stat(temp.name)
+            self.assertEqual(st.st_size, 4 * len(data))
+
+            # Check file contents
+            datafile = open(temp.name, 'r')
+            result_data = array.array('f')
+            result_data.fromfile(datafile, len(data))
+            self.assertFloatTuplesAlmostEqual(expected_result, result_data)
+
+if __name__ == '__main__':
+    gr_unittest.run(test_file_sink, "test_file_sink.xml")
diff --git a/gr-blocks/python/blocks/qa_file_source.py b/gr-blocks/python/blocks/qa_file_source.py
new file mode 100644
index 0000000000..f8ca75d79c
--- /dev/null
+++ b/gr-blocks/python/blocks/qa_file_source.py
@@ -0,0 +1,153 @@
+#!/usr/bin/env python
+#
+# Copyright 2018 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+from gnuradio import gr, gr_unittest, blocks
+import os
+import tempfile
+import pmt
+import array
+
+class test_file_source(gr_unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        os.environ['GR_CONF_CONTROLPORT_ON'] = 'False'
+        cls._datafile = tempfile.NamedTemporaryFile()
+        cls._datafilename = cls._datafile.name
+        cls._vector = range(1000)
+        with open(cls._datafilename, 'w') as f:
+            array.array('f', cls._vector).tofile(f)
+
+    @classmethod
+    def tearDownClass(cls):
+        del cls._vector
+        del cls._datafilename
+        del cls._datafile
+
+    def setUp (self):
+        self.tb = gr.top_block ()
+
+    def tearDown (self):
+        self.tb = None
+
+    def test_file_source(self):
+        expected_result = self._vector
+
+        src = blocks.file_source(gr.sizeof_float, self._datafilename)
+        snk = blocks.vector_sink_f()
+        self.tb.connect(src, snk)
+        self.tb.run()
+
+        result_data = snk.data()
+        self.assertFloatTuplesAlmostEqual(self._vector, result_data)
+        self.assertEqual(len(snk.tags()), 0)
+
+    def test_file_source_no_such_file(self):
+
+        try:
+            src = blocks.file_source(gr.sizeof_float, "___no_such_file___")
+            self.assertTrue(False)
+        except RuntimeError, e:
+            self.assertTrue(True)
+
+    def test_file_source_with_offset(self):
+        expected_result = self._vector[100:]
+
+        src = blocks.file_source(gr.sizeof_float, self._datafilename, offset=100)
+        snk = blocks.vector_sink_f()
+
+        self.tb.connect(src, snk)
+        self.tb.run()
+
+        result_data = snk.data()
+        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
+        self.assertEqual(len(snk.tags()), 0)
+
+    def test_source_with_offset_and_len(self):
+        expected_result = self._vector[100:100+600]
+
+        src = blocks.file_source(gr.sizeof_float, self._datafilename, offset=100, len=600)
+        snk = blocks.vector_sink_f()
+        self.tb.connect(src, snk)
+        self.tb.run()
+
+        result_data = snk.data()
+        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
+        self.assertEqual(len(snk.tags()), 0)
+
+    def test_file_source_can_seek_after_open(self):
+
+        src = blocks.file_source(gr.sizeof_float, self._datafilename)
+        self.assertTrue(src.seek(0, os.SEEK_SET))
+        self.assertTrue(src.seek(len(self._vector)-1, os.SEEK_SET))
+        # Seek past end of file - this will also log a warning
+        self.assertFalse(src.seek(len(self._vector), os.SEEK_SET))
+        # Negative seek - this will also log a warning
+        self.assertFalse(src.seek(-1, os.SEEK_SET))
+
+        self.assertTrue(src.seek(1, os.SEEK_END))
+        self.assertTrue(src.seek(len(self._vector), os.SEEK_END))
+        # Seek past end of file - this will also log a warning
+        self.assertFalse(src.seek(0, os.SEEK_END))
+
+        self.assertTrue(src.seek(0, os.SEEK_SET))
+        self.assertTrue(src.seek(1, os.SEEK_CUR))
+        # Seek past end of file - this will also log a warning
+        self.assertFalse(src.seek(len(self._vector), os.SEEK_CUR));
+
+
+    def test_begin_tag(self):
+        expected_result = self._vector
+
+        src = blocks.file_source(gr.sizeof_float, self._datafilename)
+        src.set_begin_tag(pmt.string_to_symbol("file_begin"))
+        snk = blocks.vector_sink_f()
+        self.tb.connect(src, snk)
+        self.tb.run()
+
+        result_data = snk.data()
+        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
+        self.assertEqual(len(snk.tags()), 1)
+
+    def test_begin_tag_repeat(self):
+        expected_result = self._vector + self._vector
+
+        src = blocks.file_source(gr.sizeof_float, self._datafilename, True)
+        src.set_begin_tag(pmt.string_to_symbol("file_begin"))
+        hd = blocks.head(gr.sizeof_float, 2 * len(self._vector))
+        snk = blocks.vector_sink_f()
+        self.tb.connect(src, hd, snk)
+        self.tb.run()
+
+        result_data = snk.data()
+        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
+        tags = snk.tags()
+        self.assertEqual(len(tags), 2)
+        self.assertEqual(str(tags[0].key), "file_begin")
+        self.assertEqual(str(tags[0].value), "0")
+        self.assertEqual(tags[0].offset, 0)
+        self.assertEqual(str(tags[1].key), "file_begin")
+        self.assertEqual(str(tags[1].value), "1")
+        self.assertEqual(tags[1].offset, 1000)
+
+if __name__ == '__main__':
+    gr_unittest.run(test_file_source, "test_file_source.xml")
diff --git a/gr-blocks/python/blocks/qa_file_source_sink.py b/gr-blocks/python/blocks/qa_file_source_sink.py
deleted file mode 100644
index 86d36c0cca..0000000000
--- a/gr-blocks/python/blocks/qa_file_source_sink.py
+++ /dev/null
@@ -1,167 +0,0 @@
-#!/usr/bin/env python
-#
-# Copyright 2013 Free Software Foundation, Inc.
-#
-# This file is part of GNU Radio
-#
-# GNU Radio is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3, or (at your option)
-# any later version.
-#
-# GNU Radio is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with GNU Radio; see the file COPYING.  If not, write to
-# the Free Software Foundation, Inc., 51 Franklin Street,
-# Boston, MA 02110-1301, USA.
-#
-
-from gnuradio import gr, gr_unittest, blocks
-import os
-import tempfile
-import pmt
-
-class test_file_source_sink(gr_unittest.TestCase):
-
-    def setUp (self):
-        os.environ['GR_CONF_CONTROLPORT_ON'] = 'False'
-        self.tb = gr.top_block ()
-
-    def tearDown (self):
-        self.tb = None
-
-    def test_001(self):
-        src_data = range(1000)
-        expected_result = range(1000)
-
-        snk2 = blocks.vector_sink_f()
-
-        with tempfile.NamedTemporaryFile() as temp:
-            src = blocks.vector_source_f(src_data)
-            snk = blocks.file_sink(gr.sizeof_float, temp.name)
-            snk.set_unbuffered(True)
-
-            self.tb.connect(src, snk)
-            self.tb.run()
-
-            src2 = blocks.file_source(gr.sizeof_float, temp.name)
-
-            self.tb.disconnect(src, snk)
-            self.tb.connect(src2, snk2)
-            self.tb.run()
-
-        result_data = snk2.data()
-        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
-        self.assertEqual(len(snk2.tags()), 0)
-
-    def test_descriptor_001(self):
-        src_data = range(1000)
-        expected_result = range(1000)
-
-        snk2 = blocks.vector_sink_f()
-
-        with tempfile.NamedTemporaryFile() as temp:
-            fhandle0 = open(temp.name, "wb")
-            fd0 = fhandle0.fileno()
-
-            src = blocks.vector_source_f(src_data)
-            snk = blocks.file_descriptor_sink(gr.sizeof_float, fd0)
-
-            self.tb.connect(src, snk)
-            self.tb.run()
-            os.fsync(fd0)
-            fhandle0.close()
-
-            fhandle1 = open(temp.name, "rb")
-            fd1 = fhandle1.fileno()
-            src2 = blocks.file_descriptor_source(gr.sizeof_float, fd1, False)
-
-            self.tb.disconnect(src, snk)
-            self.tb.connect(src2, snk2)
-            self.tb.run()
-            os.fsync(fd1)
-            fhandle1.close()
-
-        result_data = snk2.data()
-        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
-        self.assertEqual(len(snk2.tags()), 0)
-
-    def test_file_source_can_seek_after_open(self):
-        src_data = range(1000)
-
-        with tempfile.NamedTemporaryFile() as temp:
-            src = blocks.vector_source_f(src_data)
-            snk = blocks.file_sink(gr.sizeof_float, temp.name)
-            snk.set_unbuffered(True)
-
-            self.tb.connect(src, snk)
-            self.tb.run()
-
-            source = blocks.file_source(gr.sizeof_float, temp.name)
-            self.assertTrue(source.seek(0, os.SEEK_SET))
-
-    def test_begin_tag(self):
-        src_data = range(1000)
-        expected_result = range(1000)
-
-        snk2 = blocks.vector_sink_f()
-
-        with tempfile.NamedTemporaryFile() as temp:
-            src = blocks.vector_source_f(src_data)
-            snk = blocks.file_sink(gr.sizeof_float, temp.name)
-            snk.set_unbuffered(True)
-
-            self.tb.connect(src, snk)
-            self.tb.run()
-
-            src2 = blocks.file_source(gr.sizeof_float, temp.name)
-            src2.set_begin_tag(pmt.string_to_symbol("file_begin"))
-
-            self.tb.disconnect(src, snk)
-            self.tb.connect(src2, snk2)
-            self.tb.run()
-
-        result_data = snk2.data()
-        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
-        self.assertEqual(len(snk2.tags()), 1)
-
-    def test_begin_tag_repeat(self):
-        src_data = range(1000)
-        expected_result = range(1000)
-        expected_result.extend(range(1000))
-
-        snk2 = blocks.vector_sink_f()
-
-        with tempfile.NamedTemporaryFile() as temp:
-            src = blocks.vector_source_f(src_data)
-            snk = blocks.file_sink(gr.sizeof_float, temp.name)
-            snk.set_unbuffered(True)
-
-            self.tb.connect(src, snk)
-            self.tb.run()
-
-            src2 = blocks.file_source(gr.sizeof_float, temp.name, True)
-            src2.set_begin_tag(pmt.string_to_symbol("file_begin"))
-            hd = blocks.head(gr.sizeof_float, 2000)
-
-            self.tb.disconnect(src, snk)
-            self.tb.connect(src2, hd, snk2)
-            self.tb.run()
-
-        result_data = snk2.data()
-        self.assertFloatTuplesAlmostEqual(expected_result, result_data)
-        tags = snk2.tags()
-        self.assertEqual(len(tags), 2)
-        self.assertEqual(str(tags[0].key), "file_begin")
-        self.assertEqual(str(tags[0].value), "0")
-        self.assertEqual(tags[0].offset, 0)
-        self.assertEqual(str(tags[1].key), "file_begin")
-        self.assertEqual(str(tags[1].value), "1")
-        self.assertEqual(tags[1].offset, 1000)
-
-if __name__ == '__main__':
-    gr_unittest.run(test_file_source_sink, "test_file_source_sink.xml")