gr_read_file_metadata

#!/usr/bin/env python
#
# Copyright 2012 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
#

import sys
from argparse import ArgumentParser

import pmt
from gnuradio.blocks import parse_file_metadata


def main(filename, detached=False):
    handle = open(filename, "rb")

    nheaders = 0
    nread = 0
    while(True):
        # read out next header bytes
        hdr_start = handle.tell()
        header_str = handle.read(parse_file_metadata.HEADER_LENGTH)
        if(len(header_str) == 0):
            break

        # Convert from string to PMT (should be a dictionary)
        try:
            header = pmt.deserialize_str(header_str)
        except RuntimeError:
            sys.stderr.write(
                "Could not deserialize header: invalid or corrupt data file.\n")
            sys.exit(1)

        print("HEADER {0}".format(nheaders))
        info = parse_file_metadata.parse_header(header, True)

        if(info["extra_len"] > 0):
            extra_str = handle.read(info["extra_len"])
            if(len(extra_str) == 0):
                break

            try:
                extra = pmt.deserialize_str(extra_str)
            except RuntimeError:
                sys.stderr.write(
                    "Could not deserialize extras: invalid or corrupt data file.\n")
                sys.exit(1)

            print("\nExtra Header:")
            extra_info = parse_file_metadata.parse_extra_dict(
                extra, info, True)

        nheaders += 1
        nread += parse_file_metadata.HEADER_LENGTH + info["extra_len"]
        if(not detached):
            nread += info['nbytes']
        handle.seek(nread, 0)
        print("\n\n")


if __name__ == "__main__":
    description = "Read in a GNU Radio file with meta data, extracts the header and prints it."

    parser = ArgumentParser(conflict_handler="resolve",
                            description=description)
    parser.add_argument("-D", "--detached", action="store_true",
                        help="Used if header is detached.")
    parser.add_argument("file", metavar="FILE",
                        help="Input file")
    args = parser.parse_args()

    main(args.file, args.detached)