TCP/IP Client Notes

The following information applies only to the Visual PRO/5 TCP/IP Client version.

In order to run this version of Visual PRO/5, the file winsock.dll or wsock32.dll must be present within the list of directories specified in your PATH environment variable. The version of your winsock.dll or wsock32.dll must be compatible with version 1.1 of the Windows Sockets API. (Your winsock.dll or wsock32.dll file must be one which is compatible with the network/packet driver software you are using. Please refer to your networking software documentation for the version number of your winsock.dll or wsock32.dll file.)

Also, in order to successfully connect this product with a PRO/5 Data Server for the UNIX operating system, Visual PRO/5 for TCP/IP must be able to do the following:

  • Recognize the login ID you want to connect with the Data Server.

  • Resolve hostnames to IP addresses.

  • Look up Internet known services.

Setting Your Login ID

The PRO/5 Data Server requires a login ID to which it will grant permission for a connection by checking in the hosts.equiv or .rhosts file on your UNIX operating system. You must set your login ID either by setting the USERID environment variable, or by specifying your login ID using the -u command line option in Visual PRO/5. (Note that the -u option is specific to the TCP/IP port of Visual PRO/5.)

For example, starting Visual PRO/5 with the command line option -usmith will tell Visual PRO/5 to connect to a Data Server using the login "smith".

The use of the command line option -u will override the USERID environment variable.

Resolving Hostnames and Internet Known Services

The way hostnames and known services are resolved by the gethostbyname() and getservbyname() system calls depends on how they are implemented in wsock32.dll by each vendor. The following example describes how the system calls work with PC/TCP from FTP Software. Your TCP/IP software may be different.

Under PC/TCP, the location of the hosts database file is determined by the host-table entry in the [pctcp general] section of the entry in the pctcp.ini file. For example:

[pctcp general]
host-table=c:\pctcp\etc\hosts

Access to a file listing Internet services is required for the Visual PRO/5 TCP/IP Client to determine the port through which to connect to the Data Server. If no services file is available, then all connections to a Data Server will require you to supply the port number when connecting. For example:

OPEN(1)"/<myserver,port=1234>myfile"

Under PC/TCP software, the location of the Internet services file ID is determined by searching in the following sequence:

  1. The etc-dir setting in the pctcp config file. For example:

    [pctcp general]
    etc-dir=c:\pctcp\etc

  2. The current directory.

  3. The c:\etc directory.