Description:

You are required to implement a multi$-$threaded client$/$server application that counts number of

specific characters given by a user using TCP sockets. The server will accept TCP requests on a port

which is passed as an argument in the command line when starting the server. To pass the port, you

need to use service name rather than port number $($see below$).$

Client$-$Side:

The client should be multi$-$threaded. The main thread asks the user to enter two strings. The

second one In addition, it creates some other threads $($depending on the size of the second string$)$ which

are responsible to send TCP requests to the server. Each thread takes only one character from the

second string, append it to the end of the first string, and ask the corresponding thread of the server to

count the occurrence of that specific character in the given string. In other words, counting operation is

supposed to be performed by a number of threads equal the number of characters in the second string.

Every output operation on the standard output should be associated with the thread$-$ID doing that. In

addition to printing the count of each specific character, the main thread will output also the total

number of counted characters found in the first string as the sum of all returned values of the search

threads.

To run the client, you need to specify the server name and the service name in your code rather that

IP address and port number. To do so$,$ you need to edit the $/$etc$/$hosts file in your client machine

and add a line that specifies the server name as nes$416\_$count$\_$server and assign it the IP address of

your server machine. Also, you need to edit the $/$etc$/$services in your client machine and add a

line that specifies the port name as count$\_$port and assign it some value $($same port used when running

server, see below$).$ Your code should use the appropriate functions to convert between hostnames$/$IP

addresses and service$/$port$.$ See the man page of the files for more information

Server$-$Side:

The server application is required to be multi$-$threaded. The server waits for requests from the

client. For each request, a thread is created to server that request. In addition, the server main thread is

required to output the number of created threads so far.

A server thread searches the received string and return the count of the last character. It sends the

result back to the corresponding client thread and exits. Also, each thread report its finding on the

standard output together with its thread$-$ID

To run the server, you need to specify the service name $($rather than the port number$)$ on the

command line. To so$,$ you need to edit the $/$etc$/$services in your server machine and add a line

that specifies the port name as count$\_$port and assign any value greater than $1024$ if you are working

locally. To avoid conflict if working on the course server, each student is required to use a port number

for the server using the following format: $55$abc for its connection, where abc is the least significant $3$

digits of your students ID$.$ For example, a student whose ID is $12345$ will have the server listening port

$=55345$

Example: $($where Ti is the thread number$)$

client$

T$1$:Enter an Alpha$-$Numeric string to look in: hfgrtAf$1$fjhdADBFADRE$123$

T$1$:Enter characters to be counted $($as one string$)$: rA$1$

T$1$: Creating $3$ threads to count for rA$1$

T$2$: # of r$$s in the first string$=1$

T$3$: # of A$$s in the first string$=3$

T$4$: # of $1$s in the first string$=2$

T$1$: # of total occurrences $=6$

$*$note: the output order and thread numbers might differ on your machine for client and server

Server$

T$8$: waiting for client request

T$8$: creating thread $($report the thread ID$)$

T$8$: number of created threads so far $=2$changes with every creation

T$9$: received string: hfgrtAf$1$fjhdADBFADRE$123$r

T$9$: # of r$$s $=1$

T$9$: sent result back, exited.

T$8$: waiting for client request

T$8$: creating thread $($report the thread ID$)$

T$8$: number of created threads so far $=3$changes with every creation

T$10$: received string: hfgrtAf$1$fjhdADBFADRE$1231$

T$10$: # of $1$s $=2$

T$10$: sent result back, exited.

and so on for all reaming threads