1smi_config(3) SMI Management Information Library smi_config(3)
2
6 smiInit, smiExit, smiSetErrorLevel, smiGetFlags, smiSetFlags, smiLoad‐
7 Module, smiGetPath, smiSetPath, smiReadConfig - SMI library configura‐
8 tion routines
9
11 #include <smi.h>
12 int smiInit(const char *tag);
15 int smiExit();
17 void smiSetErrorLevel(int level);
19 int smiGetFlags();
21 void smiSetFlags(int userflags);
23 char *smiLoadModule(char *module);
25 int smiIsLoaded(char *module);
27 char *smiGetPath();
29 int smiSetPath(char *path);
31 int smiSetSeverity(char *pattern, int severity);
33 int smiReadConfig(char *filename, const char *tag);
35 void smiSetErrorHandler(SmiErrorHandler *smiErrorHandler);
37 typedef void (SmiErrorHandler) (char *path, int line,
39 int severity, char *msg, char *tag);
40
43 These functions provide some initialization and adjustment operations
44 for the SMI library.
45 The smiInit() function should be the first SMI function called in an
47 application. It initializes its internal structures. If tag is not
48 NULL, the global configuration file and (on UNIX systems) a user con‐
49 figuration file are read implicitly, if existent. All global statements
50 and those statements with a tag (a ``tag: '' prefix) that matches the
51 tag argument are executed. (see also CONFIGURATION FILES below). smi‐
52 Init() returns zero on success, or otherwise a negative value.
53 The smiInit() function can also be used to support multiple sets of MIB
55 data. In this case, the tag argument may be prepended by a colon and a
56 name to differentiate the data sets. Any library function call subse‐
57 quent to an smiInit("tag:dataset") call is using the specified data
58 set.
59 The smiExit() function should be called when the application no longer
61 needs any SMI information to release any allocated SMI resources.
62 The smiSetErrorLevel() function sets the pedantic level (0-9) of the
64 SMI parsers of the SMI library, currently SMIv1/v2 and SMIng. The
65 higher the level, the louder it complains. Values up to 3 should be
66 regarded as errors, higher level could be interpreted as warnings. But
67 note that this classification is some kind of personal taste. The
68 default level is 0, since usually only MIB checkers want to tune a
69 higher level.
70 The smiGetFlags() and smiSetFlags() functions allow to fetch, modify,
72 and set some userflags that control the SMI library's behaviour. If
73 SMI_FLAG_ERRORS is not set, no error messages are printed at all to
74 keep the SMI library totally quiet, which might be mandatory for some
75 applications. If SMI_FLAG_STATS is set, the library prints some module
76 statistics. If SMI_FLAG_RECURSIVE is set, the library also complains
77 about errors in modules that are read due to import statements. If
78 SMI_FLAG_NODESCR is set, no description and references strings are
79 stored in memory. This may save a huge amount of memory in case of
80 applications that do not need this information.
81 The smiSetSeverity() function allows to set the severity of all error
83 that have name prefixed by pattern to the value severity.
84 The smiLoadModule() function specifies an additional MIB module that
86 the application claims to know or an additional file path to read.
87 Only after a module is made known through this function, iterating
88 retrieval functions and retrieval functions without fully qualified
89 identifiers will return results from this module. smiLoadModule()
90 returns the name of the loaded module, of NULL if it could not be
91 loaded.
92 The smiIsLoaded() function returns a positive value if the module named
94 module is already loaded, or zero otherwise.
95 The smiGetPath() and smiSetPath() functions allow to fetch, modify, and
97 set the path that is used to search MIB modules. smiGetPath() returns
98 a copy of the current search path in the form "DIR1:DIR2:...", or NULL
99 if no path is set. The application should free this string if it is no
100 longer needed. smiSetPath() sets the search path to path.
101 The smiReadConfig() function reads the configuration file filename.
103 All global statements in the configuration file and those statements
104 with a tag (a ``tag: '' prefix) that matches the tag argument, if
105 present, are executed.
106 The smiSetErrorHandler() function allows to set a callback function
108 that is called by the MIB parsers deviating from the builtin default
109 error handler, that prints error messages to stderr. The error handler
110 has to comply with the SmiErrorHandler function type. The path, line,
111 severity, msg, and tag arguements carry the module's pathname, the line
112 number within the module, the error severity level, a textual error
113 message, and a short error name of the error being reported.
114
116 The SMI library may retrieve MIB modules from different kinds of
117 resources. Currently, SMIv1/v2 and SMIng module files are supported.
118 If in an smiLoadModule() function call a module is specified by a path
119 name (identified by containing at least one dot or slash character),
120 this is assumed to be the exact file to read. Otherwise, if a module is
121 identified by its plain module name, the correspondant file (either
122 SMIv1/2 or SMIng) is searched along a path. This path is initialized
123 with
124 /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.
125 Afterwards the optional global and user configuration files are parsed
126 for `path' commands, and finally the optional SMIPATH environment vari‐
127 able is evaluated. The `path' command argument and the environment
128 variable either start with a path separator character (`:' on UNIX-like
129 systems, `;' on MS-Windows systems) to append to the path, or end with
130 a path separator character to prepend to the path, or otherwise com‐
131 pletely replace the path. The path can also be controlled by the
132 smiGetPath() and smiSetPath() functions (see above).
133 When files are searched by a given module name, they might have no
135 extension or one of the extensions `.my', `.smiv2', `.sming', `.mib',
136 or `.txt'. However, the MIB module language is identified by the file's
137 content, not by its file name extension.
138
140 SMI library configuration files read at initialization and on demand by
141 smiReadConfig() have a simple line oriented syntax. Empty lines and
142 those starting with `#' are ignored. Other lines start with an optional
143 tag (prepended by a colon), followed by a command and options dependent
144 on the command. Tags are used to limit the scope of a command to those
145 applications that are using this tag.
146 The load command is used to preload a given MIB module. If multiple
148 modules shall be preloaded, multiple load commands must be used.
149 The path command allows to prepend or append components to the MIB mod‐
151 ule search path or to modify it completely (see also MODULE LOCATIONS
152 above).
153 The cache command allows to add an additional directory for MIB module
155 lookup as a last resort. The first argument specifies the directory and
156 the rest of the line starting from the second argument specifies the
157 caching method, which is invoked with the MIB module name appended if
158 the module is found neither in one of the regular directories nor in
159 the cache directory beforehand.
160 The level command sets the error level.
162 The hide command allows to tune the list of errors that are reported.
164 It raises all errors with names prefixed by the given pattern to sever‐
165 ity level 9. [Currently, there is no way to list the error names. RTFS:
166 error.c.]
167 Example configuration:
169 #
171 # $HOME/.smirc
172 #
173 # add a private directory
175 path :/usr/home/strauss/lib/mibs
176 # don't show any errors by default
178 level 0
179 # preload some basic modules
181 load SNMPv2-SMI
182 load SNMPv2-TC
183 load SNMPv2-CONF
184 # want to make smilint shout
186 smilint: level 8
187 # but please don't claim about
189 # any names longer than 32 chars
190 smilint: hide namelength-32
191 tcpdump: load DISMAN-SCRIPT-MIB
193 smiquery: load IF-MIB
195 smiquery: load DISMAN-SCRIPT-MIB
196
198 /etc/smi.conf global configuration file
199 $HOME/.smirc user configuration file
200 /usr/include/smi.h SMI library header file
201 /usr/share/mibs/ SMI module repository directory
202
204 libsmi(3), smi.h
205
207 (C) 1999-2001 Frank Strauss, TU Braunschweig, Germany
208 <strauss@ibr.cs.tu-bs.de>
209IBR August 22, 2001 smi_config(3)