Implement storedevs, prepare to port littlefs

kernel/fs/littlefs/scripts/teepipe.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+#
+# tee, but for pipes
+#
+# Example:
+# ./scripts/tee.py in_pipe out_pipe1 out_pipe2
+#
+# Copyright (c) 2022, The littlefs authors.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import os
+import io
+import time
+import sys
+
+
+def openio(path, mode='r', buffering=-1):
+    # allow '-' for stdin/stdout
+    if path == '-':
+        if mode == 'r':
+            return os.fdopen(os.dup(sys.stdin.fileno()), mode, buffering)
+        else:
+            return os.fdopen(os.dup(sys.stdout.fileno()), mode, buffering)
+    else:
+        return open(path, mode, buffering)
+
+def main(in_path, out_paths, *, keep_open=False):
+    out_pipes = [openio(p, 'wb', 0) for p in out_paths]
+    try:
+        with openio(in_path, 'rb', 0) as f:
+            while True:
+                buf = f.read(io.DEFAULT_BUFFER_SIZE)
+                if not buf:
+                    if not keep_open:
+                        break
+                    # don't just flood reads
+                    time.sleep(0.1)
+                    continue
+
+                for p in out_pipes:
+                    try:
+                        p.write(buf)
+                    except BrokenPipeError:
+                        pass
+    except FileNotFoundError as e:
+        print("error: file not found %r" % in_path)
+        sys.exit(-1)
+    except KeyboardInterrupt:
+        pass
+
+
+if __name__ == "__main__":
+    import sys
+    import argparse
+    parser = argparse.ArgumentParser(
+        description="tee, but for pipes.",
+        allow_abbrev=False)
+    parser.add_argument(
+        'in_path',
+        help="Path to read from.")
+    parser.add_argument(
+        'out_paths',
+        nargs='+',
+        help="Path to write to.")
+    parser.add_argument(
+        '-k', '--keep-open',
+        action='store_true',
+        help="Reopen the pipe on EOF, useful when multiple "
+            "processes are writing.")
+    sys.exit(main(**{k: v
+        for k, v in vars(parser.parse_intermixed_args()).items()
+        if v is not None}))