organize examples

This commit is largely based on work by Thiago Arrais (@thiagoarrais)
and Shane Bradfield (@l33tLumberjack). I wasn't really able to get their
PR reasonably merged onto the latest master, so I reapplied their changes
manually here and did some further improvements on that.

1 files changed, 29 insertions, 0 deletions

diff --git a/examples/simple/io_write_dumpfile.py b/examples/simple/io_write_dumpfile.py
new file mode 100644
index 00000000..ff1fd0f4
--- /dev/null
+++ b/examples/simple/io_write_dumpfile.py
@@ -0,0 +1,29 @@
+"""
+This script how to generate a mitmproxy dump file,
+as it would also be generated by passing `-w` to mitmproxy.
+In contrast to `-w`, this gives you full control over which
+flows should be saved and also allows you to rotate files or log
+to multiple files in parallel.
+"""
+import random
+import sys
+from mitmproxy import io
+
+
+class Writer:
+    def __init__(self, path):
+        if path == "-":
+            f = sys.stdout
+        else:
+            f = open(path, "wb")
+        self.w = io.FlowWriter(f)
+
+    def response(self, flow):
+        if random.choice([True, False]):
+            self.w.add(flow)
+
+
+def start():
+    if len(sys.argv) != 2:
+        raise ValueError('Usage: -s "flowriter.py filename"')
+    return Writer(sys.argv[1])