Convert binary/hex encoded string to an integer-CodePudding

Hi sorry if this is a duplicate. Have done my best to look for an answer
BACKGROUND:
I am using dpkt to try and read the src and destination ip of packets in a PCAP file. The raw data in the file is stored simply as bytes: c0 a8 00 28 => 192 168 0 40. Perfect if I was using C all would be good I could just rip this out of the file, unfortunately I am having to use python, specifically the dpkt library:
PROBLEM:
When I try to print out the ip using:

import dpkt
file = open("./PCAPfiles/somerandom.pcap", "rb")
pcap = dpkt.pcap.Reader(f)
for ts, buf in pcap:
    eth = dpkt.ethernet.Ethernet(buf)
    ip = eth.data
    print(ip.src)
    break

OUTPUT: b'\xc0\xa8\x00('
you can see its the data I want, (c0 a8 00 28 => 192 168 0 40) with "(" mapping to 40 in the ascii lookup table.
QUESTION:
How can I consistently turn b'\xc0\xa8\x00(' into c0 a8 00 28, if there is a nice function that would be nice, but if I just have to manually build a string parser that is fine.

CodePudding user response：

Just convert each byte to an int then to a string as follows:

b = b'\xc0\xa8\x00('

print(' '.join(map(str, list(b))))

Output:

192 168 0 40

CodePudding user response：

You can use bytearray() and hex() to get the hexadecimal value from an array of byte values:

s = b'\xc0\xa8\x00('
print(bytearray(s).hex())

Output:

c0a80028

Also, using a list comprehension can be much more clear solution, as it outputs directly the int values expected:

s = b'\xc0\xa8\x00('
print([i for i in bytearray(s)])

Output

[192, 168, 0, 40]

CodePudding user response：

Of course the minute after I post a question I find the answer, if I use the list() function it solves all my issues:

for integer in list(ip.src):
    print(integer)

OUTPUT: 192 168 0 40 Perfect, sometimes writing out your question can help you find an answer.