8.4. Setting Up VLINK and TLINK

The vlink and tlink programs, compiled from vlink.c and tlink.c, are small C programs which contact and interface to a running Interchange daemon. The VLINK executable is normally made setuid to the user account which runs Interchange, so that the UNIX-domain socket file can be set to secure permissions (user read-write only). It is normally not necessary for the user to do anything. They will be compiled by the configuration program. If the Interchange daemon is not running, either of the programs will display a message indicating that the server is not available. The following defines in the produced config.h should be set:

LINK_FILE

Set this to the name of the socket file that will be used for configuration, usually "/usr/local/lib/interchange/etc/socket" or the "etc/socket" under the directory chosen for the VendRoot.

LINK_HOST

Set this to the IP number of the host which should be contacted. The default of 127.0.0.1 (the local machine) is probably best for many installations.

LINK_PORT

Set this to the TCP port number that the Interchange server will monitor. The default is 7786 (the decimal ASCII codes for 'M' and 'V') and does not normally need to be changed.

LINK_TIMEOUT

Set this to the number of seconds vlink or tlink should wait before announcing that the Interchange server is not running. The default of 45 is probably a reasonable value.