getnetpath(3N)                                                  getnetpath(3N)


NAME
     setnetpath, getnetpath, endnetpath  - get 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 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).


RETURN VALUES
     setnetpath returns a handle that is used by getnetpath.  In case of an
     error, setnetpath returns NULL.  nc_perror or nc_sperror can be used to
     print out the reason for failure.  See getnetconfig(3N).

     When first called, getnetpath returns a pointer to the netconfig database
     entry corresponding to the first valid NETPATH component.  When NETPATH
     has been exhausted, getnetpath returns NULL.

     endnetpath returns 0 on success and -1 on failure (for example, if
     setnetpath was not called previously).

NOTES
     Prior to 6.5.20, these functions were present in the UNIX System V
     Networking Library (libnsl) and only available to applications linking
     against that library.  In 6.5.20, they were moved to the IRIX standard C
     library (libc).  Applications using these functions by linking against
     libnsl will continue to work on all releases of IRIX.  Authors of new
     applications which use these functions without linking against libnsl
     should be aware that their applications will not run on releases of IRIX
     prior to 6.5.20, and should use the _MIPS_SYMBOL_PRESENT macro to provide
     a graceful fallback.

SEE ALSO
     netconfig(4), getnetconfig(3N), environ(5)


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