Showing posts with label socket. Show all posts
Showing posts with label socket. Show all posts

Saturday, June 2, 2012

Compiling Happycoders libsocket in Ubuntu

 Happycoders libsocket is an object oriented and platform independent socket library for C++. It has a nice structure for both tcp and udp sockets. It runs like a charm if you want to connect a server and get the content as well as listen from a port and accept the connections.

Since package maintainers published a debian package mainly for Debian and Ubuntu distros, it can easly be installed on those systems. If you use another os the solutions is to compile it yourself. However, GCC throws an error message which can be easily solved. In order to compile the package and use it with your C++ applications, first open an console and type


so we have the source package downloaded. Extract the tar archive

gunzip libsocket-1.8.tar.gz
tar -xvf libsocket-1.8.tar 

Now we have a folder with a name of libsocket-1.8. Get in this folder and start the compilation process:


and then type


After getting some output, GCC throws an error:

make  all-recursive
make[1]: Entering directory `/tmp/socket/libsocket-1.8'
Making all in src
make[2]: Entering directory `/tmp/socket/libsocket-1.8/src'
Making all in tests
make[3]: Entering directory `/tmp/socket/libsocket-1.8/src/tests'
make[3]: Nothing to be done for `all'.
make[3]: Leaving directory `/tmp/socket/libsocket-1.8/src/tests'
make[3]: Entering directory `/tmp/socket/libsocket-1.8/src'
if /bin/bash ../libtool --mode=compile g++ -DHAVE_CONFIG_H -I. -I. -I.. -I../src    -g -O2 -Wall -ansi -pedantic -MT socket.lo -MD -MP -MF ".deps/socket.Tpo" \
   -c -o socket.lo `test -f '' || echo './'`; \
 then mv -f ".deps/socket.Tpo" ".deps/socket.Plo"; \
 else rm -f ".deps/socket.Tpo"; exit 1; \
 g++ -DHAVE_CONFIG_H -I. -I. -I.. -I../src -g -O2 -Wall -ansi -pedantic -MT socket.lo -MD -MP -MF .deps/socket.Tpo -c  -fPIC -DPIC -o .libs/socket.o In member function 'void Network::Socket::_write_str_bin(int, const string&) const': error: 'memcpy' was not declared in this scope
make[3]: *** [socket.lo] Error 1
make[3]: Leaving directory `/tmp/socket/libsocket-1.8/src'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/tmp/socket/libsocket-1.8/src'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/tmp/socket/libsocket-1.8'
make: *** [all] Error 2

When you look into to error message we can see the key point: In member function 'void Network::Socket::_write_str_bin(int, const string&) const': error: 'memcpy' was not declared in this scope

It is clear that, GCC needs memcpy to be declared before it is used. It is a function defined in the standar C package string.h and it cstring in C++. Simply open the and add the line

#include <string.h>

and compile again. After typing the make command you will get a new error message. A part of this error message is given below: In member function 'virtual std::string Network::UdpSocket::_read_line_bin(int, unsigned int)': error: 'memset' was not declared in this scope

and this is a similar error. memset is an other standard function defined in string.h in C++ and C. Simple edit the file udpsocket and add the same header

#include <string.h>

After compiling many times, GCC will throw similar errors. To cope with this
  • Include string.h in
  • Include string.h in
  • Include string.h in
  • Include string.h and stddef.h in
  • Include string.h in
After all, we you type make again, GCC compiles and produces binary outputs. Then type

sudo make install

if you want to install. Happycoders socket library is a static library by default and your application will not depent it externally. Have fun!

Tuesday, January 31, 2012

A tiny C library for client sockets

Sockets are everything in programming, especially, after the wide use of internet. Sockets are used for connecting two devices in a network using several low level protocols. At user level, those protocols are not transparent to user, that is, opening a connection and sending some string or binary data along a network is the whole thing for a general programmer.

Socket programming is not a difficult one in much of high level languages. I have used sockets in Java several times and the stuff were running like a charm. Unfortunately, same easiness is not current for C. However, it is the faster way of doing this work.

Last day, I needed to code a client socket for retrieving some data over the network. My Ubuntu was ready for the task with its installed C libraries. Since Linux sockets are a little bit detailed so there were too many terms (htons, inet_ntoa) which requires some low level knowledge of Linux sockets. For example, a C# programmer does not need to know how Windows converts an IP number to binary data and via versa. But Linux sockets are harder. But once you learn it, it is more fun.

Finally, I wrote a small library for a client socket task. The example of this code is shown below:

  1. #include <stdio.h>
  2. #include <stdlib.h>
  3. #include <string.h>
  4. #include "ClientSocket.h"
  7. int main(int argc, char** argv) {
  8. /* We will store some text in this buffer */
  9. int bufsize=1024;
  10. char buffer[bufsize];
  11. char *hostname = "";
  12. int port = 80;
  13. /* Getting ip address of into buffer */
  14. getIPAddress("", buffer);
  15. printf("Connecting to (%s) %s\n", hostname, buffer);
  16. /* Creating socket */
  17. struct ClientSocket *socket = socket_create(buffer, port);
  18. /* Connecting */
  19. socket_connect(socket);
  20. /* Sending a http request */
  21. strcpy(buffer,"GET /\n\n");
  22. socket_send(socket, buffer, strlen(buffer));
  23. /* Receiving the first #bufsize elements */
  24. socket_receive(socket, buffer, bufsize);
  25. printf("%s",buffer);
  26. /* Do not read any more. Closing */
  27. socket_close(socket);
  28. return (EXIT_SUCCESS);
  29. }

The header file of out tiny library is here:(ClientSocket.h)
  1. /*
  2. * File: ClientSocket.h
  3. * Author: Practical Code Solutions
  4. *
  5. * Created on January 31, 2012, 9:56 AM
  6. */
  8. #ifndef CLIENTSOCKET_H
  9. #define CLIENTSOCKET_H
  11. #ifdef __cplusplus
  12. extern "C" {
  13. #endif
  15. struct ClientSocket {
  16. int fd;
  17. char *ip;
  18. int port;
  19. int (*getIp)(const char *, char *);
  20. };
  22. int getIPAddress(const char *host, char *ip);
  24. struct ClientSocket *socket_create(char *ip, int port);
  26. int socket_connect(struct ClientSocket *sock);
  28. int socket_send(struct ClientSocket *sock, char *data, int len);
  30. int socket_receive(struct ClientSocket *sock, char *data, int len);
  32. int socket_close(struct ClientSocket *sock);
  36. #ifdef __cplusplus
  37. }
  38. #endif
  40. #endif /* CLIENTSOCKET_H */
The C source file of our tiny library is here: (ClientSocket.c)
  1. #include <stdlib.h>
  2. #include <stdio.h>
  3. #include <string.h>
  4. #include <arpa/inet.h>
  5. #include <sys/socket.h>
  6. #include <netdb.h>
  8. #include "ClientSocket.h"
  10. int getIPAddress(const char *host, char *ip){
  11. struct hostent *hh = gethostbyname(host);
  12. struct in_addr *add = hh->h_addr_list[0];
  13. strcpy(ip, inet_ntoa(add[0]));
  14. }
  16. struct ClientSocket *socket_create(char *ip, int port){
  17. struct ClientSocket *socket = malloc(sizeof(struct ClientSocket));
  18. socket->ip = ip;
  19. socket->port = port;
  20. socket->getIp = getIPAddress;
  21. return(socket);
  22. }
  24. int socket_connect(struct ClientSocket *sock){
  25. struct sockaddr_in addr;
  26. int result;
  27. sock->fd = socket(AF_INET, SOCK_STREAM, 0);
  28. memset((char *)&addr, 0, sizeof(addr));
  29. addr.sin_port = htons(sock->port);
  30. addr.sin_family = AF_INET;
  31. addr.sin_addr.s_addr = inet_addr(sock->ip);
  32. result = connect(sock->fd, (struct sockaddr *)&addr, sizeof(addr));
  33. return(result);
  34. }
  36. int socket_send(struct ClientSocket *sock, char *data, int len){
  37. return send(sock->fd, data, len, 0);
  38. }
  40. int socket_receive(struct ClientSocket *sock, char *data, int len){
  41. data[len-1] = '\0';
  42. return recv(sock->fd, (void *)data, len -1 , 0);
  43. }
  45. int socket_close(struct ClientSocket *sock){
  46. return close (sock->;fd);
  47. }

Tuesday, March 8, 2011

TCP sockets in C Language

A good description for Tcp sockets in C language: UPDATE at 2012/31/01 Since, this entry is quite old, but a new entry in our blog would be helpful for those are playing with linux sockets using C. Try this link.