⟩ How to check which ports are listening in my Linux Server?
Use the Command 'netstat -listen' and 'lsof -i'
Use the Command 'netstat -listen' and 'lsof -i'
What is the output of this program no 9? #include<stdio.h> #include<sys/types.h> #include<sys/socket.h> int main() { struct sockaddr_in addr; int fd; fd = socket(AF_INET,SOCK_STREAM,0); printf("%dn",fd); return 0; } a) -1 b) 3 c) error d) none of the mentioned
What is the output of this program? #include<stdio.h> #include<stdlib.h> #include<netinet/in.h> #include<sys/types.h> #include<sys/socket.h> int main() { int fd_server, fd_client, len, len_client; struct sockaddr_in add_server, add_client; char buff[10]; fd_server = socket(AF_INET,SOCK_STREAM,0); if (fd_server == -1){ perror("fd_sock"); exit(1); } len = sizeof(add_server); len_client = sizeof(add_client); if( bind(fd_server,(struct sockaddr*)&add_server,len) != 0) perror("bind"); fd_client = accept(fd_server,(struct sockaddr*)&add_client,len_client); if(fd_client == -1) perror("accept"); read(fd_client,buff,10); return 0; } a) segmentation fault b) error at the time of compilation c) syntax error d) none of the mentioned
This program can send the request to #include<stdio.h> #include<netinet/in.h> #include<sys/types.h> #include<sys/socket.h> int main() { int fd_client,fd, len; struct sockaddr_in add_server; fd_client = socket(AF_INET,SOCK_STREAM,0); if (fd_client == -1){ perror("fd_sock"); exit(1); } add_server.sin_family = AF_INET; add_server.sin_port = ntohs(4001); add_server.sin_addr.s_addr = inet_addr("193.39.0.4"); len = sizeof(add_server); fd = connect(fd_client,(struct sockaddr*)&add_server,len); if(fd == -1) perror("connect"); return 0; } a) the system having IP address 193.39.0.4 b) any system present in the network c) any system of the private network d) none of the mentioned
This program is valid for #include<stdio.h> #include<netinet/in.h> #include<sys/types.h> #include<sys/socket.h> int main() { int fd_client,fd, len; struct sockaddr_in add_server; fd_client = socket(AF_INET,SOCK_STREAM,0); if (fd_client == -1){ perror("fd_sock"); exit(1); } add_server.sin_family = AF_INET; add_server.sin_port = ntohs(4001); add_server.sin_addr.s_addr = inet_addr("144.29.8.2"); len = sizeof(add_server); fd = connect(fd_client,(struct sockaddr*)&add_server,len); return 0; } a) IPv4 b) IPv6 c) both (a) and (b) d) none of the mentioned
What is the output of this program? #include<stdio.h> #include<sys/socket.h> int main() { int ret; ret = shutdown(0,0); printf("%dn",ret); return 0; } a) 0 b) -1 c) can not be determined d) none of the mentioned
What is the problem with this server program? #include<stdio.h> #include<stdlib.h> #include<netinet/in.h> #include<sys/types.h> #include<sys/socket.h> int main() { int fd_server, fd_client, len; struct sockaddr_in add_server; fd_server = socket(AF_INET,SOCK_STREAM,0); if (fd_server == -1){ perror("fd_sock"); exit(1); } add_server.sin_family = AF_INET; add_server.sin_port = htons(4001); add_server.sin_addr.s_addr = inet_addr("122.23.1.1"); len = sizeof(add_server); if( bind(fd_server,(struct sockaddr*)&add_server,len) != 0) perror("bind"); if(listen(fd_server,5) != 0) perror("listen"); fd_client = accept(fd_server,(struct sockaddr*)&add_server,&len); if(fd_client == -1) perror("accept"); return 0; } a) it can not accept the request of any client b) it will give the segmentation fault c) there is no problem with this program d) none of the ment
What is the output of this program no 10? #include<stdio.h> #include<stdlib.h> #include<netinet/in.h> #include<sys/types.h> #include<sys/socket.h> int main() { int fd_server, fd_client, len, len_client; struct sockaddr_in add_server; fd_server = socket(AF_INET,SOCK_STREAM,0); fd_client = accept(fd_server,(struct sockaddr*)&add_server,&len); if(fd_client == -1) perror("accept"); if(listen(fd_server,5) != 0) perror("listen"); return 0; } a) syntax error b) error at the time of compilation c) segmentation fault d) none of the mentioned
What is the output of this program no 11? #include<stdio.h> #include<stdlib.h> #include<netinet/in.h> #include<sys/types.h> #include<sys/socket.h> int main() { int fd_server, fd_client, len, len_client; struct sockaddr_in add_server; fd_server = socket(AF_INET,SOCK_STREAM,0); close(fd_server); perror("accept"); if(listen(fd_server,5) != 0) perror("listen"); fd_client = accept(fd_server,(struct sockaddr*)&add_server,&len); if(fd_client == -1) return 0; } a) syntax error b) error at the time of compilation c) segmentation fault d) none of the mentioned
On which system call, this program (process) waits until the server responds? #include<stdio.h> #include<netinet/in.h> #include<sys/types.h> #include<sys/socket.h> int main() { int fd_client,fd, len; struct sockaddr_in add_server; fd_client = socket(AF_INET,SOCK_STREAM,0); if (fd_client == -1){ perror("fd_sock"); exit(1); } add_server.sin_family = AF_INET; add_server.sin_port = ntohs(4001); add_server.sin_addr.s_addr = inet_addr("127.0.0.1"); len = sizeof(add_server); fd = connect(fd_client,(struct sockaddr*)&add_server,len); if(fd == -1) perror("connect"); write(fd,"Hellon",6); return 0; } a) socket() b) connect() c) both (a) and (b) d) none of the mentioned
What is the the response of this server for this client if both programs are running on the same system? /*This is server.c*/ #include<stdio.h> #include<stdlib.h> #include<netinet/in.h> #include<sys/types.h> #include<sys/socket.h> int main() { int fd_server, fd_client, len, len_client; struct sockaddr_in add_server, add_client; char buff[10]; fd_server = socket(AF_INET,SOCK_STREAM,0); if (fd_server == -1){ perror("fd_sock"); exit(1); } add_server.sin_family = AF_INET; add_server.sin_port = htons(4001); add_server.sin_addr.s_addr = inet_addr("127.0.0.1"); len = sizeof(add_server); len = sizeof(add_client); if( bind(fd_server,(struct sockaddr*)&add_server,len) != 0) perror("bind"); if(listen(fd_server,5) != 0) perror("listen"); fd_client = accept(fd_server,(struct sockaddr*)&add_client,&len_client); if(fd_client == -1) perror("accept"); read(fd_cl