str_pkt_3_epy_block_0.py

"""
Embedded Python Block: File Source to Tagged Stream
"""

import numpy as np
from gnuradio import gr
import pmt
import os.path
import sys

class blk(gr.sync_block):
    def __init__(self):
        gr.sync_block.__init__(
            self,
            name='EPB: File Source to Tagged Stream',
            in_sig=None,
            out_sig=[np.uint8])

        global _eof
        global indx
        _eof = False
        indx = 0
        fn = "/home/barry/Documents/Gettysburg.txt"
        if (os.path.exists(fn)):
            # open input file
            global f_in
            f_in = open (fn, 'rb')
        else:
            print('The input file does not exist')
            _eof = True

    def work(self, input_items, output_items):
        global _eof
        global indx
        global f_in
        Pkt_len = 252
        # print(type(output_items[0][0]))
        while (not (_eof)):
            buff = f_in.read (Pkt_len)
            b_len = len(buff)
            if b_len == 0:
                print ('End of file')
                _eof = 1
                f_in.close()
                break
            key0 = pmt.intern("packet_len")
            val0 = pmt.from_long(b_len)
            self.add_item_tag(0, # Write to output port 0
                indx,   # Index of the tag
                key0,   # Key of the tag
                val0    # Value of the tag
                )
            # print (indx, b_len)
            indx += b_len
            i = 0
            while (i < b_len):
                output_items[0][i] = buff[i]
                i += 1
            return (b_len)