NAME

getnetpath, setnetpath, endnetpath − get, set and end netconfig entry corresponding to NETPATH component

SYNOPSIS

#include <netconfig.h>
void ∗setnetpath(void);
struct netconfig ∗getnetpath(void ∗handlep);
int endnetpath(void ∗handlep);

DESCRIPTION

The three routines described on this page are part of the UNIX System V Network Selection component.  They provide application access to the system network configuration database, /etc/netconfig, as it is “filtered” by the NETPATH environment variable [see environ(5)].  Network Selection also includes routines that access the network configuration database directly [see getnetconfig(3N)]. 

A call to setnetpath “binds” or “rewinds” NETPATH.  setnetpath must be called before the first call to getnetpath and may be called at any other time.  It returns a handle that is used by getnetpath.  setnetpath will fail if the ­netconfig database is not present.  If NETPATH is unset, setnetpath returns the number of “visible” networks in the netconfig file.  The set of visible networks constitutes a default NETPATH. 

When first called, getnetpath returns a pointer to the netconfig database entry corresponding to the first valid NETPATH component.  The netconfig entry is formatted as a netconfig structure.  On each subsequent call, getnetpath returns a pointer to the netconfig entry that corresponds to the next valid NETPATH component.  getnetpath can thus be used to search the netconfig database for all networks included in the NETPATH variable.  When NETPATH has been exhausted, getnetpath returns NULL. 

getnetpath silently ignores invalid NETPATH components.  A NETPATH component is invalid if there is no corresponding entry in the netconfig database. 

If the NETPATH variable is unset, getnetpath behaves as if NETPATH were set to the sequence of “default” or “visible” networks in the netconfig database, in the order in which they are listed. 

endnetpath may be called to “unbind” NETPATH when processing is complete, releasing resources for reuse.  Programmer’s should be aware, however, that endnetpath frees all memory allocated by setnetpath.  endnetpath returns 0 on success and −1 on failure (for example, if setnetpath was not called previously). 

SEE ALSO

getnetconfig(3N), netconfig(4), environ(5). 

  —  Networking Support Utilities