some improvements and fixed intendations
This commit is contained in:
parent
ddef20a8e7
commit
c4a3ddae50
394
client.cpp
394
client.cpp
@ -17,213 +17,215 @@
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
int create_socket;
|
||||
char buffer[BUF];
|
||||
struct sockaddr_in address;
|
||||
int size;
|
||||
int isQuit;
|
||||
int create_socket;
|
||||
char buffer[BUF];
|
||||
struct sockaddr_in address;
|
||||
int size;
|
||||
int isQuit;
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// CREATE A SOCKET
|
||||
// https://man7.org/linux/man-pages/man2/socket.2.html
|
||||
// https://man7.org/linux/man-pages/man7/ip.7.html
|
||||
// https://man7.org/linux/man-pages/man7/tcp.7.html
|
||||
// IPv4, TCP (connection oriented), IP (same as server)
|
||||
if ((create_socket = socket(AF_INET, SOCK_STREAM, 0)) == -1)
|
||||
{
|
||||
perror("Socket error");
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// CREATE A SOCKET
|
||||
// https://man7.org/linux/man-pages/man2/socket.2.html
|
||||
// https://man7.org/linux/man-pages/man7/ip.7.html
|
||||
// https://man7.org/linux/man-pages/man7/tcp.7.html
|
||||
// IPv4, TCP (connection oriented), IP (same as server)
|
||||
if ((create_socket = socket(AF_INET, SOCK_STREAM, 0)) == -1)
|
||||
{
|
||||
perror("Socket error");
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// INIT ADDRESS
|
||||
// Attention: network byte order => big endian
|
||||
memset(&address, 0, sizeof(address)); // init storage with 0
|
||||
address.sin_family = AF_INET; // IPv4
|
||||
// https://man7.org/linux/man-pages/man3/htons.3.html
|
||||
address.sin_port = htons(PORT);
|
||||
// https://man7.org/linux/man-pages/man3/inet_aton.3.html
|
||||
if (argc < 2)
|
||||
{
|
||||
inet_aton("127.0.0.1", &address.sin_addr);
|
||||
}
|
||||
else
|
||||
{
|
||||
inet_aton(argv[1], &address.sin_addr);
|
||||
}
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// INIT ADDRESS
|
||||
// Attention: network byte order => big endian
|
||||
memset(&address, 0, sizeof(address)); // init storage with 0
|
||||
address.sin_family = AF_INET; // IPv4
|
||||
// https://man7.org/linux/man-pages/man3/htons.3.html
|
||||
address.sin_port = htons(PORT);
|
||||
// https://man7.org/linux/man-pages/man3/inet_aton.3.html
|
||||
if (argc < 2)
|
||||
{
|
||||
inet_aton("127.0.0.1", &address.sin_addr);
|
||||
}
|
||||
else
|
||||
{
|
||||
inet_aton(argv[1], &address.sin_addr);
|
||||
}
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// CREATE A CONNECTION
|
||||
// https://man7.org/linux/man-pages/man2/connect.2.html
|
||||
if (connect(create_socket,
|
||||
(struct sockaddr *)&address,
|
||||
sizeof(address)) == -1)
|
||||
{
|
||||
// https://man7.org/linux/man-pages/man3/perror.3.html
|
||||
perror("Connect error - no server available");
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// CREATE A CONNECTION
|
||||
// https://man7.org/linux/man-pages/man2/connect.2.html
|
||||
if (connect(create_socket,
|
||||
(struct sockaddr *)&address,
|
||||
sizeof(address)) == -1)
|
||||
{
|
||||
// https://man7.org/linux/man-pages/man3/perror.3.html
|
||||
perror("Connect error - no server available");
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
// ignore return value of printf
|
||||
printf("Connection with server (%s) established\n",
|
||||
inet_ntoa(address.sin_addr));
|
||||
// ignore return value of printf
|
||||
printf("Connection with server (%s) established\n",
|
||||
inet_ntoa(address.sin_addr));
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// RECEIVE DATA
|
||||
// https://man7.org/linux/man-pages/man2/recv.2.html
|
||||
size = recv(create_socket, buffer, BUF - 1, 0);
|
||||
if (size == -1)
|
||||
{
|
||||
perror("recv error");
|
||||
}
|
||||
else if (size == 0)
|
||||
{
|
||||
printf("Server closed remote socket\n"); // ignore error
|
||||
}
|
||||
else
|
||||
{
|
||||
buffer[size] = '\0';
|
||||
printf("%s", buffer); // ignore error
|
||||
}
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// RECEIVE DATA
|
||||
// https://man7.org/linux/man-pages/man2/recv.2.html
|
||||
/*
|
||||
size = recv(create_socket, buffer, BUF - 1, 0);
|
||||
if (size == -1)
|
||||
{
|
||||
perror("recv error");
|
||||
}
|
||||
else if (size == 0)
|
||||
{
|
||||
printf("Server closed remote socket\n"); // ignore error
|
||||
}
|
||||
else
|
||||
{
|
||||
buffer[size] = '\0';
|
||||
printf("%s", buffer); // ignore error
|
||||
}
|
||||
*/
|
||||
|
||||
do {
|
||||
printf("Please specify a command (SEND, LIST, READ, DEL, QUIT): ");
|
||||
if (fgets(buffer, BUF - 1, stdin) != NULL)
|
||||
{
|
||||
size = strlen(buffer);
|
||||
if (buffer[size - 2] == '\r' && buffer[size - 1] == '\n')
|
||||
{
|
||||
size -= 2;
|
||||
buffer[size] = 0;
|
||||
}
|
||||
else if (buffer[size - 1] == '\n')
|
||||
{
|
||||
--size;
|
||||
buffer[size] = 0;
|
||||
}
|
||||
do {
|
||||
printf("Please specify a command (SEND, LIST, READ, DEL, QUIT): ");
|
||||
if (fgets(buffer, BUF - 1, stdin) != NULL)
|
||||
{
|
||||
size = strlen(buffer);
|
||||
if (buffer[size - 2] == '\r' && buffer[size - 1] == '\n')
|
||||
{
|
||||
size -= 2;
|
||||
buffer[size] = 0;
|
||||
}
|
||||
else if (buffer[size - 1] == '\n')
|
||||
{
|
||||
--size;
|
||||
buffer[size] = 0;
|
||||
}
|
||||
|
||||
isQuit = strcmp(buffer, "QUIT") == 0;
|
||||
isQuit = strcmp(buffer, "QUIT") == 0;
|
||||
|
||||
if (strcmp(buffer, "SEND") == 0)
|
||||
{
|
||||
char sender[BUF], receiver[BUF], subject[81], message[BUF * 10];
|
||||
printf("Sender: ");
|
||||
fgets(sender, BUF - 1, stdin);
|
||||
printf("Receiver: ");
|
||||
fgets(receiver, BUF - 1, stdin);
|
||||
printf("Subject: ");
|
||||
fgets(subject, 80, stdin);
|
||||
printf("Message: \n");
|
||||
char line[BUF];
|
||||
message[0] = '\0';
|
||||
while (true)
|
||||
{
|
||||
fgets(line, BUF - 1, stdin);
|
||||
if (strcmp(line, ".\n") == 0)
|
||||
break;
|
||||
strcat(message, line);
|
||||
}
|
||||
snprintf(buffer, sizeof(buffer), "SEND\n%s%s%s%s.\n", sender, receiver, subject, message);
|
||||
}
|
||||
else if (strcmp(buffer, "LIST") == 0)
|
||||
{
|
||||
char username[BUF];
|
||||
printf("Username: ");
|
||||
fgets(username, BUF - 1, stdin);
|
||||
snprintf(buffer, sizeof(buffer), "LIST\n%s", username);
|
||||
}
|
||||
else if (strcmp(buffer, "READ") == 0)
|
||||
{
|
||||
char username[BUF], msgNum[10];
|
||||
printf("Username: ");
|
||||
fgets(username, BUF - 1, stdin);
|
||||
printf("Message Number: ");
|
||||
fgets(msgNum, 9, stdin);
|
||||
snprintf(buffer, sizeof(buffer), "READ\n%s%s", username, msgNum);
|
||||
}
|
||||
else if (strcmp(buffer, "DEL") == 0)
|
||||
{
|
||||
char username[BUF], msgNum[10];
|
||||
printf("Username: ");
|
||||
fgets(username, BUF - 1, stdin);
|
||||
printf("Message Number: ");
|
||||
fgets(msgNum, 9, stdin);
|
||||
snprintf(buffer, sizeof(buffer), "DEL\n%s%s", username, msgNum);
|
||||
}
|
||||
if (strcmp(buffer, "SEND") == 0)
|
||||
{
|
||||
char sender[BUF], receiver[BUF], subject[81], message[BUF * 10];
|
||||
printf("Sender: ");
|
||||
fgets(sender, BUF - 1, stdin);
|
||||
printf("Receiver: ");
|
||||
fgets(receiver, BUF - 1, stdin);
|
||||
printf("Subject: ");
|
||||
fgets(subject, 80, stdin);
|
||||
printf("Message: ");
|
||||
char line[BUF];
|
||||
message[0] = '\0';
|
||||
while (true)
|
||||
{
|
||||
fgets(line, BUF - 1, stdin);
|
||||
if (strcmp(line, ".\n") == 0)
|
||||
break;
|
||||
strcat(message, line);
|
||||
}
|
||||
snprintf(buffer, sizeof(buffer), "SEND\n%s%s%s%s.\n", sender, receiver, subject, message);
|
||||
}
|
||||
else if (strcmp(buffer, "LIST") == 0)
|
||||
{
|
||||
char username[BUF];
|
||||
printf("Username: ");
|
||||
fgets(username, BUF - 1, stdin);
|
||||
snprintf(buffer, sizeof(buffer), "LIST\n%s", username);
|
||||
}
|
||||
else if (strcmp(buffer, "READ") == 0)
|
||||
{
|
||||
char username[BUF], msgNum[10];
|
||||
printf("Username: ");
|
||||
fgets(username, BUF - 1, stdin);
|
||||
printf("Message Number: ");
|
||||
fgets(msgNum, 9, stdin);
|
||||
snprintf(buffer, sizeof(buffer), "READ\n%s%s", username, msgNum);
|
||||
}
|
||||
else if (strcmp(buffer, "DEL") == 0)
|
||||
{
|
||||
char username[BUF], msgNum[10];
|
||||
printf("Username: ");
|
||||
fgets(username, BUF - 1, stdin);
|
||||
printf("Message Number: ");
|
||||
fgets(msgNum, 9, stdin);
|
||||
snprintf(buffer, sizeof(buffer), "DEL\n%s%s", username, msgNum);
|
||||
}
|
||||
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
// SEND DATA
|
||||
// https://man7.org/linux/man-pages/man2/send.2.html
|
||||
// send will fail if connection is closed, but does not set
|
||||
// the error of send, but still the count of bytes sent
|
||||
int size = strlen(buffer);
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
// SEND DATA
|
||||
// https://man7.org/linux/man-pages/man2/send.2.html
|
||||
// send will fail if connection is closed, but does not set
|
||||
// the error of send, but still the count of bytes sent
|
||||
int size = strlen(buffer);
|
||||
|
||||
if ((send(create_socket, buffer, size + 1, 0)) == -1)
|
||||
{
|
||||
// in case the server is gone offline we will still not enter
|
||||
// this part of code: see docs: https://linux.die.net/man/3/send
|
||||
// >> Successful completion of a call to send() does not guarantee
|
||||
// >> delivery of the message. A return value of -1 indicates only
|
||||
// >> locally-detected errors.
|
||||
// ... but
|
||||
// to check the connection before send is sense-less because
|
||||
// after checking the communication can fail (so we would need
|
||||
// to have 1 atomic operation to check...)
|
||||
perror("send error");
|
||||
break;
|
||||
}
|
||||
if ((send(create_socket, buffer, size + 1, 0)) == -1)
|
||||
{
|
||||
// in case the server is gone offline we will still not enter
|
||||
// this part of code: see docs: https://linux.die.net/man/3/send
|
||||
// >> Successful completion of a call to send() does not guarantee
|
||||
// >> delivery of the message. A return value of -1 indicates only
|
||||
// >> locally-detected errors.
|
||||
// ... but
|
||||
// to check the connection before send is sense-less because
|
||||
// after checking the communication can fail (so we would need
|
||||
// to have 1 atomic operation to check...)
|
||||
perror("send error");
|
||||
break;
|
||||
}
|
||||
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
// RECEIVE FEEDBACK
|
||||
// consider: reconnect handling might be appropriate in somes cases
|
||||
// How can we determine that the command sent was received
|
||||
// or not?
|
||||
// - Resend, might change state too often.
|
||||
// - Else a command might have been lost.
|
||||
//
|
||||
// solution 1: adding meta-data (unique command id) and check on the
|
||||
// server if already processed.
|
||||
// solution 2: add an infrastructure component for messaging (broker)
|
||||
//
|
||||
size = recv(create_socket, buffer, BUF - 1, 0);
|
||||
if (size == -1)
|
||||
{
|
||||
perror("recv error");
|
||||
break;
|
||||
}
|
||||
else if (size == 0)
|
||||
{
|
||||
printf("Server closed remote socket\n"); // ignore error
|
||||
break;
|
||||
}
|
||||
else
|
||||
{
|
||||
buffer[size] = '\0';
|
||||
printf("<< %s\n", buffer); // ignore error
|
||||
if (strcmp("OK", buffer) != 0)
|
||||
{
|
||||
fprintf(stderr, "<< Server error occured, abort\n");
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
} while (!isQuit);
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
// RECEIVE FEEDBACK
|
||||
// consider: reconnect handling might be appropriate in somes cases
|
||||
// How can we determine that the command sent was received
|
||||
// or not?
|
||||
// - Resend, might change state too often.
|
||||
// - Else a command might have been lost.
|
||||
//
|
||||
// solution 1: adding meta-data (unique command id) and check on the
|
||||
// server if already processed.
|
||||
// solution 2: add an infrastructure component for messaging (broker)
|
||||
//
|
||||
size = recv(create_socket, buffer, BUF - 1, 0);
|
||||
if (size == -1)
|
||||
{
|
||||
perror("recv error");
|
||||
break;
|
||||
}
|
||||
else if (size == 0)
|
||||
{
|
||||
printf("Server closed remote socket\n"); // ignore error
|
||||
break;
|
||||
}
|
||||
else
|
||||
{
|
||||
buffer[size] = '\0';
|
||||
printf("<< %s\n", buffer); // ignore error
|
||||
/*if (strcmp("OK", buffer) != 0) // needs proper verification, since responses vary between commands
|
||||
{
|
||||
fprintf(stderr, "<< Server error occured, abort\n");
|
||||
break;
|
||||
}*/
|
||||
}
|
||||
}
|
||||
} while (!isQuit);
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// CLOSES THE DESCRIPTOR
|
||||
if (create_socket != -1)
|
||||
{
|
||||
if (shutdown(create_socket, SHUT_RDWR) == -1)
|
||||
{
|
||||
// invalid in case the server is gone already
|
||||
perror("shutdown create_socket");
|
||||
}
|
||||
if (close(create_socket) == -1)
|
||||
{
|
||||
perror("close create_socket");
|
||||
}
|
||||
create_socket = -1;
|
||||
}
|
||||
////////////////////////////////////////////////////////////////////////////
|
||||
// CLOSES THE DESCRIPTOR
|
||||
if (create_socket != -1)
|
||||
{
|
||||
if (shutdown(create_socket, SHUT_RDWR) == -1)
|
||||
{
|
||||
// invalid in case the server is gone already
|
||||
perror("shutdown create_socket");
|
||||
}
|
||||
if (close(create_socket) == -1)
|
||||
{
|
||||
perror("close create_socket");
|
||||
}
|
||||
create_socket = -1;
|
||||
}
|
||||
|
||||
return EXIT_SUCCESS;
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user