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Concept explainers
//Server.c
#include "csapp.h"
void *thread(void *vargp);
int main(int argc, char *argv[])
{
int listenfd;
socklen_t clientlen;
char client_hostname[MAXLINE], client_port[MAXLINE];
struct sockaddr_storage clientaddr;
pthread_t tid;
if (argc != 2)
{
fprintf(stderr, "usage: %s <port>\n", argv[0]);
exit(0);
}
listenfd = Open_listenfd(argv[1]);
while (1)
{
clientlen = sizeof(struct sockaddr_storage);
int *connfdp = Malloc(sizeof(int));
*connfdp = Accept(listenfd, (SA *)&clientaddr, &clientlen);
Getnameinfo((SA *)&clientaddr, clientlen,
client_hostname, MAXLINE,
client_port, MAXLINE, 0);
printf("Connected to (%s, %s)\n", client_hostname, client_port);
Pthread_create(&tid, NULL, thread, connfdp);
}
}
void *thread(void *vargp)
{
int connfd = *((int *)vargp);
Pthread_detach(pthread_self());
Free(vargp);
size_t n;
rio_t rio;
int option;
char firstName[256];
char lastName[256];
char filefirstName[256];
char filelastName[256];
int age;
char major[256];
char buffer[256];
Rio_readinitb(&rio, connfd);
while (1)
{
bzero(buffer, 256);
if ((n = Rio_readlineb(&rio, buffer, 255)) == 0)
{
printf("Connection closed\n");
break;
}
option = atoi(buffer);
if (option == 1)
{
bzero(firstName, 256);
n = rio_readlineb(&rio, firstName, 255);
if (n < 0)
{
perror("ERROR reading from socket\n");
exit(1);
}
bzero(lastName, 256);
n = rio_readlineb(&rio, lastName, 255);
if (n < 0)
{
perror("ERROR reading from socket\n");
exit(1);
}
firstName[strlen(firstName) - 1] = '\0';
lastName[strlen(lastName) - 1] = '\0';
FILE *fptr;
int found = 0;
fptr = fopen("studentRecords.txt", "r");
if (fptr == NULL)
{
printf("Error opening file!\n");
exit(1);
}
bzero(buffer, 256);
while (fscanf(fptr, "%[^,],%[^,],%d,%[^\n]\n", filefirstName, filelastName, &age, major) != EOF)
{
if (strcmp(firstName, filefirstName) == 0 && strcmp(lastName, filelastName) == 0)
{
found = 1;
sprintf(buffer, "%s,%s,%d,%s\n", firstName, lastName, age, major);
n = rio_writen(connfd, buffer, strlen(buffer));
if (n < 0)
{
perror("ERROR writing to socket\n");
exit(1);
}
}
}
fclose
(fptr);
if (!found)
{
bzero(buffer, 256);
sprintf(buffer, "No record found!!\n");
n = rio_writen(connfd, buffer, strlen(buffer));
if (n < 0)
{
perror("ERROR writing to socket\n");
exit(1);
}
}
bzero(buffer, 256);
sprintf(buffer, "\n");
n = rio_writen(connfd, buffer, strlen(buffer));
if (n < 0)
{
perror("ERROR writing to socket\n");
exit(1);
}
}
else if (option == 2)
{
// Close the connection
Close(connfd);
break;
}
}
return NULL;
}
//client.c
#include "csapp.h"
int main(int argc, char *argv[])
{
int sockfd;
ssize_t n;
rio_t rio;
char buffer[256];
int option;
char firstName[256];
char lastName[256];
char major[256];
if (argc < 3)
{
fprintf(stderr, "usage %s hostname port\n", argv[0]);
exit(0);
}
sockfd = Open_clientfd(argv[1], argv[2]);
rio_readinitb(&rio, sockfd);
while (1)
{
printf("\n(1) Search record\n(2) Terminate\nSelect an option [1 or 2]: ");
bzero(buffer, 256);
if (fgets(buffer, 255, stdin) == NULL)
{
perror("ERROR reading value");
exit(1);
}
option = atoi(buffer);
n = rio_writen(sockfd, buffer, strlen(buffer));
if (n < 0)
{
perror("ERROR writing to socket");
exit(1);
}
if (option == 1)
{
printf("Enter first name: ");
bzero(firstName, 256);
if (fgets(firstName, 255, stdin) == NULL)
{
perror("ERROR reading value");
exit(1);
}
printf("Enter last name: ");
bzero(lastName, 256);
if (fgets(lastName, 255, stdin) == NULL)
{
perror("ERROR reading value");
exit(1);
}
n = rio_writen(sockfd, firstName, strlen(firstName));
if (n < 0)
{
perror("ERROR writing to socket");
exit(1);
}
n = rio_writen(sockfd, lastName, strlen(lastName));
if (n < 0)
{
perror("ERROR writing to socket");
exit(1);
}
bzero(buffer, 256);
printf("Message from server:\n");
while ((n = rio_readlineb(&rio, buffer, 255)) != 0)
{
if (strlen(buffer) == 1)
{
break;
}
buffer[strlen(buffer) - 1] = '\0';
printf("%s \n", buffer);
if (strcmp(buffer, "No record found!!") == 0)
{
break;
}
}
if (n < 0)
{
perror("ERROR reading from socket\n");
exit(1);
}
}
else if (option == 2)
{
close(sockfd);
printf("Connection Closed!!\n");
break;
}
}
exit(0);
}
Can you help me demonstrate of these two files?
as well as a problem solving approach, discussion of data structures,
Step by stepSolved in 3 steps
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