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Daytime Server Case Study

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Ans1: MAKEME

# _*_Makefile_*_

# target: dependencies
#
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all: udp_client

UDPdaytime client: gcc -o udp_daytime udp_daytime.c

clean: rm udp_daytime

README

to execute the program.

1: use cd (-- removed HTML --) to go the directory where the file is stored.

2: Run make -f MakeFile.

3: Run./udp_daytime ip.

4: Output of the daytime service will be displayed.

5: To clear the executable file run make -f MakeFile clean

Explanation:

In this program, we created a udp socket and we connect it to a daytime server specified by user on port 13(default) We sent to the server an arbitrary message to trigger a response.
The server then responds with a message containing the date and time in an unspecified format …show more content…

buffer which will hold the response from the daytime server struct hostent* host; //our struct which will hold the resolved hostname information

//creating a UDP socket daytime_socket = socket(AF_INET, SOCK_DGRAM, 0); if(daytime_socket < 0){ printf("Unable to create a socket\n"); return -1; }

//performing a gethostbyname to resolve a domain name if the user does not supply and ip address host = gethostbyname(argv[1]); if(host == NULL){ printf("Host %s could not be resolved\n", argv[1]); return -1; }

//zero out the sockaddr_in struct in preparation of storing connection info bzero(&daytime_server,sizeof(daytime_server));

daytime_server.sin_family = AF_INET; //specify internet family (IPV4) bcopy((char *)host->h_addr, (char *)&daytime_server.sin_addr.s_addr, host->h_length); //copy the resolved ip address into the struct daytime_server.sin_port = htons(PORT); //copy the port into the struct

//send our trigger message if(sendto(daytime_socket, message, strlen(message), 0, (struct sockaddr *)&daytime_server, size_daytime_server) < 0){ printf("Could not send message %s\n", message); return -1; }

//zero out our recieving buffer and wait for a response from the daytime server bzero(buffer, BUFFSIZE); if(recvfrom(daytime_socket, buffer,

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