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In most cases a user has no interest in which transport provider handles a network operation, and the default network search path established by the system administrator (the netconfig file) is used to locate a transport provider available for connection. However, if a user or the system administrator wants to influence the choices made by applications, the search path can be modified using a new standard shell variable, NETPATH. NETPATH is similar to the PATH variable.
NETPATH consists of a colon-separated list of network IDs. Each network ID corresponds to the network_id field of a record in the netconfig database. A literal colon can be embedded as ``\:'' and a literal backslash as ``\\''. An empty component in NETPATH (signified by a beginning colon, an ending colon, or two successive colons) is not a valid entry because the empty string is not a valid network ID. NETPATH is described in environ(5).
The NETPATH environment variable is not set in /etc/profile. It can, however, be set in a user's $HOME/.profile.
Both users and system administrators should be aware that the set of default networks is different for routines that access netconfig directly and routines that access netconfig via the NETPATH environment variable. For routines that access netconfig directly (see getnetconfig(3N)), the set of default networks is the entire netconfig file; the set of default networks for the routines that access netconfig via NETPATH is the visible networks in the netconfig file (see getnetpath(3N)). A network is visible if the system administrator has included a v flag in the flag field. If NETPATH is unset, these visible networks are the default search path for this second group of access routines.