NAME

       smiInit,  smiExit,  smiSetErrorLevel,  smiGetFlags,  smiSetFlags,  smiLoadModule, smiGetPath, smiSetPath,
       smiReadConfig - SMI library configuration routines

SYNOPSIS

       #include <smi.h>

       int smiInit(const char *tag);

       int smiExit();

       void smiSetErrorLevel(int level);

       int smiGetFlags();

       void smiSetFlags(int userflags);

       char *smiLoadModule(char *module);

       int smiIsLoaded(char *module);

       char *smiGetPath();

       int smiSetPath(char *path);

       int smiSetSeverity(char *pattern, int severity);

       int smiReadConfig(char *filename, const char *tag);

       void smiSetErrorHandler(SmiErrorHandler *smiErrorHandler);

       typedef void (SmiErrorHandler) (char *path, int line,
                           int severity, char *msg, char *tag);

DESCRIPTION

       These functions provide some initialization and adjustment operations for the SMI library.

       The smiInit() function should be the first SMI function called in  an  application.  It  initializes  its
       internal  structures.  If  tag  is  not  NULL, the global configuration file and (on UNIX systems) a user
       configuration file are read implicitly, if existent. All global statements and those  statements  with  a
       tag  (a  ``tag:  ''  prefix)  that  matches the tag argument are executed.  (see also CONFIGURATION FILES
       below).  smiInit() returns zero on success, or otherwise a negative value.

       The smiInit() function can also be used to support multiple sets of MIB  data.  In  this  case,  the  tag
       argument may be prepended by a colon and a name to differentiate the data sets. Any library function call
       subsequent to an smiInit("tag:dataset") call is using the specified data set.

       The smiExit() function should be called when the application no  longer  needs  any  SMI  information  to
       release any allocated SMI resources.

       The  smiSetErrorLevel()  function  sets  the  pedantic level (0-9) of the SMI parsers of the SMI library,
       currently SMIv1/v2 and SMIng.  The higher the level, the louder it complains. Values up to  3  should  be
       regarded  as errors, higher level could be interpreted as warnings.  But note that this classification is
       some kind of personal taste.  The default level is 0, since usually only MIB  checkers  want  to  tune  a
       higher level.

       The smiGetFlags() and smiSetFlags() functions allow to fetch, modify, and set some userflags that control
       the SMI library's behaviour.  If SMI_FLAG_ERRORS is not set, no error messages are printed at all to keep
       the  SMI library totally quiet, which might be mandatory for some applications. If SMI_FLAG_STATS is set,
       the library prints some module statistics. If SMI_FLAG_RECURSIVE is set, the library also complains about
       errors  in modules that are read due to import statements. If SMI_FLAG_NODESCR is set, no description and
       references strings are stored in memory. This may save a huge amount of memory in  case  of  applications
       that do not need this information.

       The  smiSetSeverity() function allows to set the severity of all error that have name prefixed by pattern
       to the value severity.

       The smiLoadModule() function specifies an additional MIB module that the application claims to know or an
       additional  file  path  to  read.   Only  after  a  module is made known through this function, iterating
       retrieval functions and retrieval functions without fully qualified identifiers will return results  from
       this module. smiLoadModule() returns the name of the loaded module, of NULL if it could not be loaded.

       The smiIsLoaded() function returns a positive value if the module named module is already loaded, or zero
       otherwise.

       The smiGetPath() and smiSetPath() functions allow to fetch, modify, and set the  path  that  is  used  to
       search  MIB modules.  smiGetPath() returns a copy of the current search path in the form "DIR1:DIR2:...",
       or NULL if no path is set.  The  application  should  free  this  string  if  it  is  no  longer  needed.
       smiSetPath() sets the search path to path.

       The  smiReadConfig()  function  reads  the  configuration  file  filename.   All global statements in the
       configuration file and those statements with a tag (a ``tag: '' prefix) that matches the tag argument, if
       present, are executed.

       The  smiSetErrorHandler()  function  allows  to set a callback function that is called by the MIB parsers
       deviating from the builtin default error handler, that prints error messages to stderr. The error handler
       has  to  comply with the SmiErrorHandler function type. The path, line, severity, msg, and tag arguements
       carry the module's pathname, the line number within the module, the error severity level, a textual error
       message, and a short error name of the error being reported.

MODULE LOCATIONS

       The SMI library may retrieve MIB modules from different kinds of resources. Currently, SMIv1/v2 and SMIng
       module files are supported.  If in an smiLoadModule() function call a module is specified by a path  name
       (identified  by  containing at least one dot or slash character), this is assumed to be the exact file to
       read. Otherwise, if a module is identified by its plain  module  name,  the  correspondant  file  (either
       SMIv1/2    or    SMIng)    is    searched    along    a    path.    This   path   is   initialized   with
       /usr/share/mibs/ietf:/usr/share/mibs/iana:/usr/share/mibs/irtf:/usr/share/mibs/site:/usr/share/mibs/tubs:/usr/share/pibs/ietf:/usr/share/pibs/site:/usr/share/pibs/tubs.
       Afterwards  the  optional global and user configuration files are parsed for `path' commands, and finally
       the optional SMIPATH environment variable is evaluated. The `path' command argument and  the  environment
       variable  either  start  with  a  path  separator  character (`:' on UNIX-like systems, `;' on MS-Windows
       systems) to append to the path, or end with a path  separator  character  to  prepend  to  the  path,  or
       otherwise  completely  replace  the  path.   The  path  can  also  be  controlled by the smiGetPath() and
       smiSetPath() functions (see above).

       When files are searched by a given module name, they might have no extension or  one  of  the  extensions
       `.my',  `.smiv2',  `.sming',  `.mib',  or  `.txt'.  However, the MIB module language is identified by the
       file's content, not by its file name extension.

CONFIGURATION FILES

       SMI library configuration files read at initialization and on demand by  smiReadConfig()  have  a  simple
       line  oriented  syntax.  Empty  lines  and those starting with `#' are ignored. Other lines start with an
       optional tag (prepended by a colon), followed by a command and options dependent on the command. Tags are
       used to limit the scope of a command to those applications that are using this tag.

       The  load command is used to preload a given MIB module. If multiple modules shall be preloaded, multiple
       load commands must be used.

       The path command allows to prepend or append components to the MIB module search path  or  to  modify  it
       completely (see also MODULE LOCATIONS above).

       The cache command allows to add an additional directory for MIB module lookup as a last resort. The first
       argument specifies the directory and the rest of the line starting from the second argument specifies the
       caching  method, which is invoked with the MIB module name appended if the module is found neither in one
       of the regular directories nor in the cache directory beforehand.

       The level command sets the error level.

       The hide command allows to tune the list of errors that are reported.  It raises all  errors  with  names
       prefixed  by  the given pattern to severity level 9. [Currently, there is no way to list the error names.
       RTFS: error.c.]

       Example configuration:

         #
         # $HOME/.smirc
         #

         # add a private directory
         path :/usr/home/strauss/lib/mibs

         # don't show any errors by default
         level 0

         # preload some basic modules
         load SNMPv2-SMI
         load SNMPv2-TC
         load SNMPv2-CONF

         # want to make smilint shout
         smilint: level 8

         # but please don't claim about
         # any names longer than 32 chars
         smilint: hide namelength-32

         tcpdump: load DISMAN-SCRIPT-MIB

         smiquery: load IF-MIB
         smiquery: load DISMAN-SCRIPT-MIB

FILES

       /etc/smi.conf    global configuration file
       $HOME/.smirc               user configuration file
       ${prefix}/include/smi.h   SMI library header file
       /usr/share/mibs/     SMI module repository directory

SEE ALSO

       libsmi(3), smi.h

AUTHOR

       (C) 1999-2001 Frank Strauss, TU Braunschweig, Germany <strauss@ibr.cs.tu-bs.de>