GETNETCONFIG(3NSL) Networking Services Library Functions GETNETCONFIG(3NSL)


NAME


getnetconfig, setnetconfig, endnetconfig, getnetconfigent,
freenetconfigent, nc_perror, nc_sperror - get network configuration
database entry

SYNOPSIS


#include <netconfig.h>


struct netconfig *getnetconfig(void *handlep);


void *setnetconfig(void);


int endnetconfig(void *handlep);


struct netconfig *getnetconfigent(const char *netid);


void freenetconfigent(struct netconfig *netconfigp);


void nc_perror(const char *msg);


char *nc_sperror(void);


DESCRIPTION


The library routines described on this page are part of the Network
Selection component. They provide the application access to the system
network configuration database, /etc/netconfig. In addition to the
routines for accessing the netconfig database, Network Selection
includes the environment variable NETPATH (see environ(5)) and the
NETPATH access routines described in getnetpath(3NSL).


getnetconfig() returns a pointer to the current entry in the netconfig
database, formatted as a struct netconfig. Successive calls will return
successive netconfig entries in the netconfig database. getnetconfig()
can be used to search the entire netconfig file. getnetconfig() returns
NULL at the end of the file. handlep is the handle obtained through
setnetconfig().


A call to setnetconfig() has the effect of ``binding'' to or
``rewinding'' the netconfig database. setnetconfig() must be called
before the first call to getnetconfig() and may be called at any other
time. setnetconfig() need not be called before a call to
getnetconfigent(). setnetconfig() returns a unique handle to be used by
getnetconfig().


endnetconfig() should be called when processing is complete to release
resources for reuse. handlep is the handle obtained through
setnetconfig(). Programmers should be aware, however, that the last call
to endnetconfig() frees all memory allocated by getnetconfig() for the
struct netconfig data structure. endnetconfig() may not be called before
setnetconfig().


getnetconfigent() returns a pointer to the struct netconfig structure
corresponding to netid. It returns NULL if netid is invalid (that is,
does not name an entry in the netconfig database).


freenetconfigent() frees the netconfig structure pointed to by netconfigp
(previously returned by getnetconfigent()).


nc_perror() prints a message to the standard error indicating why any of
the above routines failed. The message is prepended with the string msg
and a colon. A NEWLINE is appended at the end of the message.


nc_sperror() is similar to nc_perror() but instead of sending the
message to the standard error, will return a pointer to a string that
contains the error message.


nc_perror() and nc_sperror() can also be used with the NETPATH access
routines defined in getnetpath(3NSL).

RETURN VALUES


setnetconfig() returns a unique handle to be used by getnetconfig(). In
the case of an error, setnetconfig() returns NULL and nc_perror() or
nc_sperror() can be used to print the reason for failure.


getnetconfig() returns a pointer to the current entry in the netconfig()
database, formatted as a struct netconfig. getnetconfig() returns NULL
at the end of the file, or upon failure.


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


On success, getnetconfigent() returns a pointer to the struct netconfig
structure corresponding to netid; otherwise it returns NULL.


nc_sperror() returns a pointer to a buffer which contains the error
message string. This buffer is overwritten on each call. In
multithreaded applications, this buffer is implemented as thread-specific
data.

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | MT-Safe |
+---------------+-----------------+

SEE ALSO


getnetpath(3NSL), netconfig(4), attributes(5), environ(5)


December 30, 1996 GETNETCONFIG(3NSL)