.\"

.\" $Id: smi_config.3.in 4432 2006-05-29 16:21:11Z strauss $

.\"

.TH smi_config 3  "August 22, 2001" "IBR" "SMI Management Information Library"

.SH NAME

.\" START OF MAN PAGE COPIES

smiInit,

smiExit,

smiSetErrorLevel,

smiGetFlags,

smiSetFlags,

smiLoadModule,

smiGetPath,

smiSetPath,

smiReadConfig

.\" END OF MAN PAGE COPIES

\- SMI library

configuration routines

.SH SYNOPSIS

.nf

.B #include <smi.h>

.RS

.RE

.sp

.BI 

.RE

.sp

.BI "int smiInit(const char *" tag );

.RE

.sp

.B "int smiExit();"

.RE

.sp

.BI "void smiSetErrorLevel(int " level );

.RE

.sp

.BI "int smiGetFlags();"

.RE

.sp

.BI "void smiSetFlags(int " userflags );

.RE

.sp

.BI "char *smiLoadModule(char *" module );

.RE

.sp

.BI "int smiIsLoaded(char *" module );

.RE

.sp

.BI "char *smiGetPath();"

.RE

.sp

.BI "int smiSetPath(char *" path );

.RE

.sp

.BI "int smiSetSeverity(char *" pattern ", int " severity );

.RE

.sp

.BI "int smiReadConfig(char *" filename ", const char *" tag );

.RE

.sp

.BI "void smiSetErrorHandler(SmiErrorHandler *" smiErrorHandler );

.RE

typedef void (SmiErrorHandler) (char *path, int line,

				int severity, char *msg, char *tag);

.fi

.SH DESCRIPTION

These functions provide some initialization and adjustment operations

for the SMI library.

.PP

The \fBsmiInit()\fP function should be the first SMI function called

in an application. It initializes its internal structures. If \fItag\fP 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 \fBtag\fP argument are executed. 

(see also CONFIGURATION FILES below).

\fBsmiInit()\fP returns zero on success, or otherwise a negative value.

.PP

The \fBsmiInit()\fP function can also be used to support multiple sets

of MIB data. In this case, the \fBtag\fP argument may be prepended by

a colon and a name to differentiate the data sets. Any library

function call subsequent to an \fBsmiInit("tag:dataset")\fP call is

using the specified data set.

.PP

The \fBsmiExit()\fP function should be called when the application

no longer needs any SMI information to release any allocated SMI

resources.

.PP

The \fBsmiSetErrorLevel()\fP 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.

.PP

The \fBsmiGetFlags()\fP and \fBsmiSetFlags()\fP functions allow to

fetch, modify, and set some \fIuserflags\fP that control the SMI

library's behaviour.  If \fBSMI_FLAG_ERRORS\fP 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 \fBSMI_FLAG_STATS\fP is set, the

library prints some module statistics. If \fBSMI_FLAG_RECURSIVE\fP is set,

the library also complains about errors in modules that are read due

to import statements. If \fBSMI_FLAG_NODESCR\fP 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.

.PP

The \fBsmiSetSeverity()\fP function allows to set the severity of

all error that have name prefixed by \fBpattern\fP to the value \fBseverity\fP.

.PP

The \fBsmiLoadModule()\fP function specifies an additional MIB \fImodule\fP

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. \fBsmiLoadModule()\fP returns the

name of the loaded module, of NULL if it could not be loaded.

.PP

The \fBsmiIsLoaded()\fP function returns a positive value if the

module named \fImodule\fP is already loaded, or zero otherwise.

.PP

The \fBsmiGetPath()\fP and \fBsmiSetPath()\fP functions allow to

fetch, modify, and set the path that is used to search MIB modules.

\fBsmiGetPath()\fP 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. \fBsmiSetPath()\fP sets the search path to

\fIpath\fP.

.PP

The \fBsmiReadConfig()\fP function reads the configuration file \fIfilename\fP.

All global statements in the configuration file and those statements with

a tag (a ``tag: '' prefix) that matches the \fBtag\fP argument, if present,

are executed.

.PP

The \fBsmiSetErrorHandler()\fP 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 \fBSmiErrorHandler\fP function type. The \fBpath\fP,

\fBline\fP, \fBseverity\fP, \fBmsg\fP, and \fPtag\fP 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.

.SH "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 \fBsmiLoadModule()\fP 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/local/share/mibs/ietf:/usr/local/share/mibs/iana:/usr/local/share/mibs/irtf:/usr/local/share/mibs/site:/usr/local/share/mibs/tubs:/usr/local/share/pibs/ietf:/usr/local/share/pibs/site:/usr/local/share/pibs/tubs.

Afterwards the optional global and user configuration files are parsed for

`path' commands, and finally the optional \fBSMIPATH\fP 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 \fBsmiGetPath()\fP 

and \fBsmiSetPath()\fP functions (see above).

.PP

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.

.SH "CONFIGURATION FILES"

SMI library configuration files read at initialization and on demand

by \fBsmiReadConfig()\fP 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. 

.PP

The \fBload\fP command is used to preload a given MIB module. If multiple

modules shall be preloaded, multiple \fBload\fP commands must be used.

.PP

The \fBpath\fP command allows to prepend or append components to the

MIB module search path or to modify it completely (see 

also MODULE LOCATIONS above).

.PP

The \fBcache\fP 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.

.PP

The \fBlevel\fP command sets the error level.

.PP

The \fBhide\fP 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.]

.PP

Example configuration:

.nf

  #

  # $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

.fi

.SH "FILES"

.nf

${prefix}/etc/smi.conf    global configuration file

$HOME/.smirc               user configuration file

${prefix}/include/smi.h   SMI library header file

/usr/local/share/mibs/     SMI module repository directory

.fi

.SH "SEE ALSO"

.BR libsmi "(3), "

.BR smi.h

.SH "AUTHOR"

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

.br