Example A-4 shows a TCP/IP server accepting a connection from the auxiliary server. You can access this file online in TCPIP$EXAMPLES:TCPIP$TCP_SERVER_IPC_AUXS.C.

In this example, the TCP/IP server accepts a connection from the auxiliary server, sends the string "Hello, world!" and immediately closes the connection and terminates. For this example to work correctly, you need to create a one-line command procedure and issue the SET SERVICE command after you compile and link the program, as follows:

1. Compile and link the sample program TCPIP$EXAMPLES:TCPIP$TCP_SERVER_IPC_AUXS.C. Depending on your compiler, you can compile and link this program in any of the following ways:
   • DEC C compiler:

     $ CC /PREFIX=ALL TCPIP$TCP_SERVER_IPC_AUXS.C $ LINK TCPIP$TCP_SERVER_IPC_AUXS

   • DEC C++ compiler:

     $ CXX /PREFIX=ALL/DEFINE=VMS TCPIP$TCP_SERVER_IPC_AUXS.C $ LINK TCPIP$TCP_SERVER_IPC_AUXS

   • VAX C compiler:
     To link this program with VAX C, you must have the following entries in your .opt file:

     SYS$LIBRARY:TCPIP$IPC.OLB/LIB SYS$SHARE:VAXCRTL.EXE/SHARE

     
     Then, you can link and compile as follows:

     $ CC /VAXC TCPIP$TCP_SERVER_IPC_AUXS.C $ LINK TCPIP$TCP_SERVER_IPC_AUXS, - SYS$LIBRARY:TCPIP$IPC/LIB, - SYS$INPUT/OPTIONS SYS$SHARE:TCPIP$IPC_SHR/SHARE SYS$SHARE:VAXCRTL.EXE/SHARE

2. Create a command procedure, named HELLO_STARTUP.COM, that consists of the following line:

   $ RUN ddcu:[dir]TCPIP$TCP_SERVER_IPC_AUXS

   
   where ddcu:[dir] is the device and directory where the file resides.

3. Issue the following:

   TCPIP> SET SERVICE HELLO /PORT=1234 /USER=username /PROCESS=HI_WORLD - _TCPIP> /FILE=ddcu:[dir]HELLO_STARTUP.COM TCPIP>ENABLE SERVICE HELLO

   
   where username is your user name and ddcu:[dir] is the device and directory where the files reside.

Example A-4 TCP/IP Server Accepting a Connection from the Auxiliary Server

#include <socket.h> #include <unixio.h> #include <string.h> #include <tcpip$inetdef.h> main() { int s; char *message = "Hello, world!\r\n"; s = socket(TCPIP$C_AUXS, 0, 0); write(s, message, strlen(message)); close(s); }

A.5 TCP/IP Client Using the IPC Socket Interface

This example creates a socket of type SOCK_STREAM (TCP), initiates a connection to the remote host, sends a message to the remote host, and closes the connection. Error messages are printed to the screen.

This example is portable to UNIX. The include files are conditionally defined for both systems, and "perror" is used for error reporting.

Depending on your compiler, you can compile and link this program in any of the following ways:

• DEC C compiler:

  $ CC /PREFIX=ALL TCPIP$TCP_CLIENT_IPC.C $ LINK TCPIP$TCP_CLIENT_IPC

• DEC C++ compiler:

  $ CXX /PREFIX=ALL/DEFINE=VMS TCPIP$TCP_CLIENT_IPC.C $ LINK TCPIP$TCP_CLIENT_IPC

• VAX C compiler:
  To link this program with VAX C, you must have the following entries in your .opt file:

  SYS$LIBRARY:TCPIP$IPC.OLB/LIB SYS$SHARE:VAXCRTL.EXE/SHARE

  
  Then, you can link and compile as follows:

  $ CC /VAXC TCPIP$TCP_CLIENT_IPC.C $ LINK TCPIP$TCP_CLIENT_IPC, - SYS$LIBRARY:TCPIP$IPC/LIB, - SYS$INPUT/OPTIONS SYS$SHARE:TCPIP$IPC_SHR/SHARE SYS$SHARE:VAXCRTL.EXE/SHARE

Example A-5 TCP/IP Client Using the IPC Socket Interface

#if defined(VMS) || defined(__VMS) #include <stdlib.h> #include <unixio.h> #include <errno.h> #include <types.h> #include <stdio.h> #include <socket.h> #include <in.h> #include <netdb.h> /* Change hostent to comply with BSD 4.3*/ #include <inet.h> #include <tcpip$inetdef.h> /* INET symbol definitions */ #else #include <errno.h> #include <sys/types.h> #include <stdio.h> #include <sys/socket.h> #include <netinet/in.h> #include <netdb.h> #include <arpa/inet.h> #include <sys/uio.h> #endif /* * MACRO DEFINITIONS */ #ifndef vms #define TRUE 1 #define FALSE 0 #endif void cleanup(int shut, int socket); /*--------------------------------------------------------------------*/ main(int argc, char **argv) { int sock_1; /* Socket */ static char message[] = "Hi there."; static struct sockaddr_in sock2_name; /* Address struct for socket2*/ struct hostent hostentstruct; /* Storage for hostent data */ struct hostent *hostentptr; /* Pointer to hostent data */ static char hostname[256]; /* Name of local host */ int flag; int retval; /* Helpful for debugging */ int shut = FALSE; /* Flag to cleanup */ /* * Check input parameters. */ if (argc != 3 ) { printf("Usage: client hostname portnumber.\n"); exit(EXIT_FAILURE); } /* * Open socket 1: AF_INET, SOCK_STREAM. */ if ((sock_1 = socket (AF_INET, SOCK_STREAM, 0)) == -1) { perror( "socket"); exit(EXIT_FAILURE); } /* *Get pointer to network data structure for socket 2 (remote host). */ if ((hostentptr = gethostbyname (argv[1])) == NULL) { perror( "gethostbyname"); cleanup(shut, sock_1); } /* * Copy hostent data to safe storage. */ hostentstruct = *hostentptr; /* * Fill in the name & address structure for socket 2. */ sock2_name.sin_family = hostentstruct.h_addrtype; sock2_name.sin_port = htons(atoi(argv[2])); sock2_name.sin_addr = * ((struct in_addr *) hostentstruct.h_addr); /* * Connect socket 1 to sock2_name. */ retval = connect(sock_1, (struct sockaddr *)&sock2_name, sizeof (sock2_name)); if (retval) { perror("connect"); cleanup(shut, sock_1); } /* * Send message to socket 2. */ flag = 0; /* maybe 0 or MSG_OOB */ retval = send(sock_1, message ,sizeof (message), flag); if (retval < 0) { perror ("send"); shut = TRUE; } /* * Call cleanup to shut down and close socket. */ cleanup(shut, sock_1); } /* end main */ /*-----------------------------------------------------------*/ void cleanup(int shut, int socket) { int retval; /* * Shut down socket completely -- only if it was connected */ if (shut) { retval = shutdown(socket,2); if (retval == -1) perror ("shutdown"); } /* * Close socket. */ retval = close (socket); if (retval) perror ("close"); exit(EXIT_SUCCESS); }