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Simple Server file program, file always doesn't exist

i recently tried a tutorial on how to create a simple file server program with python. i don't know why everytime i check whether the file exists or not, it always tells me the file doesn't exist, here is the code
# server.py
import socket
import threading
import os
def RetFile(FileName, sock):
FileName = sock.recv(1024)
exists = os.path.isfile(FileName)
if exists:
sock.send(str.encode("EXISTS " + str(os.path.getsize(FileName))))
UserResponce = sock.recv(1024)
if UserResponce[:2] == "OK":
with open(FileName, 'rb') as f:
bytesToSend = f.read(1024)
sock.send(bytesToSend)
while bytesToSend != "":
bytesToSend = f.read(1024)
sock.send(bytesToSend)
else:
sock.send(str.encode("ERR"))
sock.close()
def Main():
host = '127.0.0.1'
port = 5001
s = socket.socket()
s.bind((host, port))
s.listen(5)
print('Server Started')
while True:
conn, addr = s.accept()
print('Client Connected -> ', str(addr))
t = threading.Thread(target=RetFile, args=("retrThread", conn))
t.start()
if __name__ == '__main__':
Main()
# client.py
import socket
def Main():
host = '127.0.0.1'
port = 5001
s = socket.socket()
s.connect((host, port))
filename = input('File Name -> ')
if filename != 'q':
s.send(str.encode(filename))
data = s.recv(1024)
if data[:6] == "EXISTS ":
filesize = float(data[6:])
message = input('File Exists: ' + str(filesize) + ' Bytes, Download? (Y/N) -> ')
if message == 'Y':
s.send(str.encode("OK"))
f = open('new_' + filename, 'wb')
data = s.recv(1024)
totalRecv = len(data)
f.write(data)
while totalRecv < filesize:
data = s.recv(1024)
totalRecv += len(data)
f.write(data)
print("{0:.2f}".format((totalRecv / float(filesize)) * 100) + "% Done!")
print('Download Complete')
else:
print("File Doesn't Exist")
s.close()
if __name__ == '__main__':
Main()
so where is the error of the code? the tutorial uses python 2.x and i use 3.x so i have some minor changes, and i'm new to this language so any help would be appreciated, thank you!

There were some issues in you code mostly related to byte conversion . you cannot send string on socket interface if you are using python 3 or above, with python 2 it works fine. So every message has to be changed to bytes before sending on socket i have fixed all such issues . Download is working fine
Fixed Server
# server.py
import socket
import threading
import os
def RetrFile(name, sock):
filename = sock.recv(1024)
if os.path.isfile(filename):
sock.send(b"Exist " + str(os.path.getsize(filename)).encode())
userResponse = sock.recv(1024)
if userResponse.decode() == 'OK':
with open(filename, 'rb') as f:
bytesToSend = f.read(1024)
while bytesToSend.decode() != "":
sock.send(bytesToSend)
bytesToSend = f.read(1024)
else:
sock.send(b"ERR")
sock.close()
def Main():
host = '127.0.0.1'
port = 5000
s = socket.socket()
s.bind((host, port))
s.listen(5)
print("server started.")
while True:
c, addr = s.accept()
print("client connected ip:<" + str(addr) + ">")
t = threading.Thread(target=RetrFile, args=("retrThread", c))
t.start()
if __name__ == '__main__':
Main()
Fixed Client
# client.py
import socket
def Main():
host = '127.0.0.1'
port = 5000
s = socket.socket()
s.connect((host, port))
filename = bytearray(input("filename.. ").encode())
if filename != 'q':
s.send(filename)
data = s.recv(1024)
if data[:6].decode().rstrip().upper() == 'EXIST':
filesize = data[6:].decode().rstrip()
message = input("File exists, " + filesize+ "Bytes, download..? (Y/N)")
if message.upper() == 'Y':
totalRecv = 0
s.send(b'OK')
f = open('new_' + filename.decode(), 'wb')
data = s.recv(1024)
while data.decode() != "":
totalRecv += len(data)
data = s.recv(1024)
f.write(data)
print("{:2f}".format((totalRecv/float(filesize))*100)+ "Done")
print("Download complete")
else:
print("File doesn't exist")
if __name__ == '__main__':
Main()

Apart from the fact that a file may not exist, there is one obvious problem:
if data[:6] == "EXISTS ":
can never be True because data[:6] is a string of 6 characters, and "EXISTS " is 7 characters long.

Tcp sockets to send and receive files, using python

I am trying to make simple client server program to send and receive file form server using tcp sockets. As far as getting files from server is not an issue, server creates a file with the same name and put data in that file but when it comes to putting files to server,sometimes it works great but always chance so mostly server is getting file name along with file contents and instead of writing that to file, it writes both filename and contents as new file name and that file remains empty. Will be great help if someone can suggest any solution.
server.py
import socket
import sys
HOST = 'localhost'
PORT = 3820
socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket.bind((HOST, PORT))
socket.listen(1)
while (1):
conn, addr = socket.accept()
print 'New client connected ..'
reqCommand = conn.recv(1024)
print 'Client> %s' %(reqCommand)
if (reqCommand == 'quit'):
break
#elif (reqCommand == lls):
#list file in server directory
else:
string = reqCommand.split(' ', 1) #in case of 'put' and 'get' method
reqFile = string[1]
if (string[0] == 'put'):
with open(reqFile, 'wb') as file_to_write:
data=conn.recv(1024)
while True:
if not data:
break
else:
file_to_write.write(data)
data=conn.recv(1024)
file_to_write.close()
break
print 'Receive Successful'
elif (string[0] == 'get'):
with open(reqFile, 'rb') as file_to_send:
for data in file_to_send:
conn.sendall(data)
print 'Send Successful'
conn.close()
socket.close()
client.py
import socket
import sys
HOST = 'localhost' # server name goes in here
PORT = 3820
def put(commandName):
socket1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket1.connect((HOST, PORT))
socket1.send(commandName)
string = commandName.split(' ', 1)
inputFile = string[1]
with open('clientfolder/'+inputFile, 'rb') as file_to_send:
data=file_to_send.read(1024)
while(data):
socket1.send(data)
data=file_to_send.read(1024)
file_to_send.close()
print 'PUT Successful'
socket1.close()
return
def get(commandName):
socket1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket1.connect((HOST, PORT))
socket1.send(commandName)
string = commandName.split(' ', 1)
inputFile = string[1]
with open('clientfolder/'+inputFile, 'wb') as file_to_write:
while True:
data = socket1.recv(1024)
# print data
if not data:
break
# print data
file_to_write.write(data)
file_to_write.close()
print 'GET Successful'
socket1.close()
return
msg = raw_input('Enter your name: ')
while(1):
print 'Instruction'
print '"put [filename]" to send the file the server '
print '"get [filename]" to download the file from the server '
print '"ls" to list all files in this directory'
print '"lls" to list all files in the server'
print '"quit" to exit'
sys.stdout.write('%s> ' % msg)
inputCommand = sys.stdin.readline().strip()
if (inputCommand == 'quit'):
socket.send('quit')
break
# elif (inputCommand == 'ls')
# elif (inputCommand == 'lls')
else:
string = inputCommand.split(' ', 1)
if (string[0] == 'put'):
put(inputCommand)
elif (string[0] == 'get'):
get(inputCommand)
#current working directory is server location
#get will get file from current directory to clientfolder directory.

TCP is a streaming protocol, so you have to design message breaks into your protocol. For example:
s.send('put filename')
s.send('data')
Can be received as:
s.recv(1024)
# 'put filenamedata'
So buffer data received and only extract full messages. One way is to send the size of a message before the message.

Socket programming client send and receive file at same time

I am trying this scenario:
Client sends file to server
Server updates on file and save it
Sends updated file back to client
Steps 1 and 2 are done correctly as I wanted but when client finishes sending the socket closes. I've tried this code but its not working. Any suggestions?
Client:
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
H = socket.gethostname()
P = 1111
s.connect((H,P))
with open('File.txt', 'rb') as fileName:
for data in fileName:
s.sendall(data)
with open('ReFile.txt', 'wb') as File:
while True:
data = s.recv(1024)
print data
if not data:
break
File.write(data)
File.close()
Server:
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
H= socket.gethostname()
P = 1111
s.bind((H, P))
s.listen(6)
c, address = s.accept()
print 'Connection with ' , address
with open('ReFile.txt', 'wb') as RecFile:
while True:
data = c.recv(1024)
print data
if not data:
break
RecFile.write(data)
RecFile.write("updated version")
RecFile.close()
with open('ReFile.txt', 'rb') as file:
for data in file:
s.sendall(data)
s.close()

Try this:
Server:
import socket
s = socket.socket()
H = socket.gethostname()
P = 1111
s.bind((H, P))
s.listen(6)
c, address = s.accept()
print 'Connection with ', address
lenF = int(c.recv(1024))
if lenF != 0:
c.sendall('Send data')
data = c.recv(lenF)
data += "\nUpdated Version"
RecFile = open('ReFile.txt','w')
RecFile.write(str(data))
RecFile.close()
fileN = open('ReFile.txt')
data = fileN.read(-1)
fileN.close()
lenF = len(data)
c.send(str(lenF))
if c.recv(5) == 'Ready':
c.send(data)
Here I am using lenF variable to get the size of file that I am getting from the client.
Client:
import socket
s = socket.socket()
H = socket.gethostname()
P = 1111
s.connect((H,P))
fileName = open('file.txt')
data = fileName.read(-1)
fileName.close()
dataL = int(len(data))
s.send(str(dataL))
validCheck = s.recv(9)
if validCheck == 'Send data':
print 'Sending file.......'
s.send(data)
dataL = int(s.recv(1024))
if dataL != 0:
s.send('Ready')
data = s.recv(dataL)
File = open('ReFile.txt','w')
File.write(data)
File.close()
Here I am using dataL variable to receive data length(file) and sending it.

Python File Server, login function not working

I made a python file server a while back and just recently came back to it. It is a very simple program but i wanted to add some more features to it, one of those being to add some security. For this reason i made a hashed login password and put that in a .txt file stored on the server computer. The way the program is supposed to work is every time the client connects to the server they must enter a password. Then the raw_entry is sent through a socket and checked on the server side if it is correct, if is is not then the user has two more tries to enter the password. For some reason this is not working.
The server:
from passlib.hash import pbkdf2_sha256
import socket
import threading
import os
def login():
loop = 1
while loop <= 3:
passwd = sock.recv(1024)
with open('passtor.txt', 'r') as f:
hash = f.read()
if pbkdf2_sha256.verify(passwd, hash):
s.send("Access Granted")
loop = 4
else:
s.send("Verification Failure")
loop += 1
if loop == 3:
sock.close()
def RetrFile(name, sock):
filename = sock.recv(1024)
if os.path.isfile(filename):
sock.send("EXISTS " + str(os.path.getsize(filename)))
userResponse = sock.recv(1024)
if userResponse[:2] == 'OK':
with open(filename, 'rb') as f:
bytesToSend = f.read(1024)
sock.send(bytesToSend)
while bytesToSend != "":
bytesToSend = f.read(1024)
sock.send(bytesToSend)
else:
sock.send("ERR ")
sock.close()
try:
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
#s.connect(('google.com', 0))
host = s.getsockname()[0]
port = 5000
s = socket.socket()
s.bind((host,port))
s.listen(5)
print "File Server Initiated"
print("Server Address-> " + host + " <-")
while True:
c, addr = s.accept()
print "Client Connected ip-> " + str(addr) + " <-"
t1 = threading.Thread(target=login, args=("RetrThread", c))
t2 = threading.Thread(target=RetrFile, args=("RetrThread", c))
t1.start()
t2.start()
s.close()
except:
print("Program Error, \nTermination Complete")
The client:
import socket
host = '127.0.0.1'
port = 5000
s = socket.socket()
s.connect((host, port))
loop = True
while loop == True:
passwd = raw_input("Admin Password-> ")
s.send(passwd)
answer = s.recv(1024)
if answer == 'Verification Failure':
loop = True
print(answer)
elif answer == 'Access Granted':
loop = False
print(answer)
filename = raw_input("Filename? -> ")
if filename != 'q':
s.send(filename)
data = s.recv(1024)
if data[:6] == 'EXISTS':
filesize = long(data[6:])
message = raw_input("File exists, " + str(filesize) +"Bytes, download? (Y/N)? -> ")
if message == 'Y':
s.send("OK")
f = open('new_'+filename, 'wb')
data = s.recv(1024)
totalRecv = len(data)
f.write(data)
while totalRecv < filesize:
data = s.recv(1024)
totalRecv += len(data)
f.write(data)
print "{0:.2f}".format((totalRecv/float(filesize))*100)+ "% Done"
print "Download Complete!"
f.close()
else:
print "File Does Not Exist!"
s.close()

You are passing two arguments to the login function here:
t1 = threading.Thread(target=login, args=("RetrThread", c))
They are not declared in the function declaration:
def login():
Either remove the args parameter from the call to threading.Thread or add the arguments to the function declaration.

Send contents of directory to client - python socket

I'm trying to send the contents of the c: drive back to the client. I'm using the os.listdir() function to generate the list but when I send it back to the client and try to print, I get nothing. How can I print the list that I get for os.listdir()?
Here is my client code:
import socket
import sys
import os
HOST = 'localhost'
PORT = 8082
size = 1024
def ls():
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST,PORT))
s.send(userInput)
result = s.recv(size)
print result
s.close()
return
def put(commandName):
socket1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket1.connect((HOST, PORT))
socket1.send(commandName)
string = commandName.split(' ', 1)
inputFile = string[1]
with open(inputFile, 'rb') as file_to_send:
for data in file_to_send:
socket1.sendall(data)
print 'PUT Successful'
socket1.close()
return
def get(commandName):
socket1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket1.connect((HOST, PORT))
socket1.send(commandName)
string = commandName.split(' ', 1)
inputFile = string[1]
with open(inputFile, 'wb') as file_to_write:
while True:
data = socket1.recv(1024)
print data
if not data:
break
print data
file_to_write.write(data)
file_to_write.close()
print 'GET Successful'
#socket1.close()
return
done = False
while not done:
userInput = raw_input()
if "quit" == userInput:
done = True
elif "ls" == userInput:
ls()
else:
string = userInput.split(' ', 1)
if (string[0] == 'put'):
put(userInput)
elif (string[0] == 'get'):
get(userInput)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST,PORT))
s.send(userInput)
data = s.recv(size)
s.close()
print 'Received:', data'
And server code:
import socket
import os
import sys
host = ''
port = 8082
backlog = 5
size = 1024
serverID = socket.gethostbyname(socket.gethostname())
info = 'SERVER ID: {} port: {}'.format(serverID, port)
print info
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host,port))
s.listen(backlog)
done = False
# Loop until client sends 'quit' to server
while not done:
client, address = s.accept()
data = client.recv(size)
print "Server received: ", data
if data:
client.send("Server Says... " + data)
if data == "quit":
done = True
elif data == "ls":
data = os.listdir("C://")
client.send(data[0])
else:
string = data.split(' ', 1)
dataFile = string[1]
if (string[0] == 'put'):
with open(dataFile, 'wb') as file_to_write:
while True:
data = client.recv(1024)
if not data:
break
file_to_write.write(data)
file_to_write.close()
break
print 'Receive Successful'
elif (string[0] == 'get'):
with open(dataFile, 'rb') as file_to_send:
for data in file_to_send:
client.send(data)
print 'Send Successful'
client.close()
s.close()
print "Server exiting."