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| author | Rainer Gerhards <rgerhards@adiscon.com> | 2008-02-26 09:05:07 +0000 |
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| committer | Rainer Gerhards <rgerhards@adiscon.com> | 2008-02-26 09:05:07 +0000 |
| commit | f22d142a538deaec341317464626c4dece41be7a (patch) | |
| tree | 14db648482cb3c6cc3f951dc2dc90a1b275d5e16 /doc/rainerscript.html | |
| parent | b33a62b92c57d6c613dfc6e427bbe1eed3af0e1c (diff) | |
| download | rsyslog-f22d142a538deaec341317464626c4dece41be7a.tar.gz rsyslog-f22d142a538deaec341317464626c4dece41be7a.tar.xz rsyslog-f22d142a538deaec341317464626c4dece41be7a.zip | |
added some user doc on RainerScript
Diffstat (limited to 'doc/rainerscript.html')
| -rw-r--r-- | doc/rainerscript.html | 78 |
1 files changed, 49 insertions, 29 deletions
diff --git a/doc/rainerscript.html b/doc/rainerscript.html index 6ffd4c37..ef0e41cb 100644 --- a/doc/rainerscript.html +++ b/doc/rainerscript.html @@ -1,37 +1,57 @@ <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html><head> -<meta http-equiv="Content-Language" content="en"><title>RainerScript ABNF</title> +<meta http-equiv="Content-Language" content="en"><title>RainerScript</title> </head> <body> -<h1>RainerScript ABNF</h1> -<p>This is the formal definition of RainerScript, as supported by -rsyslog configuration. Please note that this currently is working -document and the actual implementation may be quite different.</p> -<p>The -first glimpse of RainerScript will be available as part of rsyslog -3.12.0 expression support. However, the 3.12. series of rsyslog will -have a partial script implementaiton, which will not necessariy be -compatible with the later full implementation. So if you use it, be -prepared for some config file changes as RainerScript evolves.</p> -<p>C-like comments (/* some comment */) are supported in all pure -RainerScript lines. However, legacy-mapped lines do not support them. -All lines support the hash mark "#" as a comment initiator. Everything -between the hash and the end of line is a comment (just like // in C++ -and many other languages).</p> -<h2>Formal Definition</h2> -<p>Below is the formal language definitionin ABNF (RFC 2234) -format: <br> -</p> -<pre>; <span style="font-weight: bold;">all of this is a working document and may change!</span> -- rgerhards, 2008-02-24<br><br>script := *stmt<br>stmt := (if_stmt / block / vardef / run_s / load_s)<br>vardef := "var" ["scope" = ("global" / "event")] <br>block := "begin" stmt "end"<br>load_s := "load" constraint ("module") modpath params ; load mod only if expr is true<br>run_s := "run" constraint ("input") name<br>constraint:= "if" expr ; constrains some one-time commands<br>modpath := expr<br>params := ["params" *1param *("," param) "endparams"]<br>param := paramname) "=" expr<br>paramname := [*(obqualifier ".") name]<br>modpath:= ; path to module<br>?line? := cfsysline / cfli<br>cfsysline:= BOL "$" *char EOL ; how to handle the first line? (no EOL in front!)<br>BOL := ; Begin of Line - implicitely set on file beginning and after each EOL<br>EOL := 0x0a ;LF<br>if_stmt := "if" expr "then"<br>old_filter:= BOL facility "." severity ; no whitespace allowed between BOL and facility!<br>facility := "*" / "auth" / "authpriv" / "cron" / "daemon" / "kern" / "lpr" / <br> "mail" / "mark" / "news" / "security" / "syslog" / "user" / "uucp" / <br> "local0" .. "local7" / "mark"<br> ; The keyword security should not be used anymore<br> ; mark is just internal<br>severity := TBD ; not really relevant in this context<br><br>; and now the actual expression<br>expr := e_and *("or" e_and)<br>e_and := e_cmp *("and" e_cmp)<br>e_cmp := val 0*1(cmp_op val)<br>val := term *(("+" / "-" / "&") term)<br>term := factor *(("*" / "/" / "%") factor)<br>factor := ["not"] ["-"] terminal<br>terminal := var / constant / function / ( "(" expr ")" )<br>function := name "(" *("," expr) ")"<br>var := "$" varname<br>varname := msgvar / sysvar<br>msgvar := name<br>sysvar := "$" name<br>name := alpha *(alnum)<br>constant := string / number<br>string := simpstr / tplstr ; tplstr will be implemented in next phase<br>simpstr := "'" *char "'" ; use your imagination for char ;)<br>tplstr := '"' template '"' ; not initially implemented<br>number := ["-"] 1*digit ; 0nn = octal, 0xnn = hex, nn = decimal<br>cmp_op := "==" / "!=" / "<>" / "<" / ">" / "<=" / ">=" / "contains" / "startswith"<br>digit := %x30-39<br>alpha := "a" ... "z" # all letters<br>alnum :* alpha / digit / "_"<br></pre> -<h2>Samples</h2> -<p>Some samples of RainerScript:</p><p>define function IsLinux<br>begin<br> if $environ contains "linux" then return true else return false<br>end</p><p>load if IsLinux() 'imklog.so' params name='klog' endparams /* load klog under linux only */<br>run if IsLinux() input 'klog'<br>load 'ommysql.so'</p><p>if $message contains "error" then<br> action<br> type='ommysql.so', queue.mode='disk', queue.highwatermark = 300,<br> action.dbname='events', action.dbuser='uid',<br> - [?action.template='templatename'?] or [?action.sql='insert into -table... values('&$facility&','&$severity&...?]<br> endaction<br><br>... or ...</p><p>define action writeMySQL<br> type='ommysql.so', queue.mode='disk', queue.highwatermark = 300,<br> action.dbname='events', action.dbuser='uid',<br> [?action.template='templatename'?] or [?action.sql='insert into table... values('<span style="font-family: monospace;"> &</span> $facility & ',' & $severity &...?]<br> endaction</p><p>if $message contains "error" then action writeMySQL</p><p>ALTERNATE APPROACH</p><p>define function IsLinux(<br> if $environ contains "linux" then return true else return false<br>)</p><p>load if IsLinux() 'imklog.so' params name='klog' endparams /* load klog under linux only */<br>run if IsLinux() input 'klog'<br>load 'ommysql.so'</p><p>if $message contains "error" then<br> action(<br> type='ommysql.so', queue.mode='disk', queue.highwatermark = 300,<br> action.dbname='events', action.dbuser='uid',<br> - [?action.template='templatename'?] or [?action.sql='insert into -table... values('&$facility&','&$severity&...?]<br> )<br><br>... or ...</p><p>define action writeMySQL(<br> type='ommysql.so', queue.mode='disk', queue.highwatermark = 300,<br> action.dbname='events', action.dbuser='uid',<br> - [?action.template='templatename'?] or [?action.sql='insert into -table... values('&$facility&','&$severity&...?]<br> )</p><p>if $message contains "error" then action writeMySQL(action.dbname='differentDB')</p><p></p><p>[<a href="rsyslog_conf.html">rsyslog.conf overview</a>] +<h1>RainerScript</h1> +<p><b>RainerScript is a scripting language specifically +designed and well-suited +for processing network events and configuring event processors</b> +(with the most prominent sample being syslog). While RainerScript is +theoritically usable with various softwares, it currently is being +used, and developed for, rsyslog. Please note that RainerScript may not +be abreviated as rscript, because that's somebody elses trademark.</p> +<p>RainerScript is currently under development. It has its first +appearance in rsyslog 3.12.0, where it provides complex expression +support. However, this is only a very partial implementatio of the +scripting language. Due to technical restrictions, the final +implementation will have a slightly different syntax. So while you are +invited to use the full power of expresssions, you unfortunatley need +to be prepared to change your configuration files at some later points. +Maintaining backwards-compatibility at this point would cause us to +make too much compromise. Defering the release until everything is +perfect is also not a good option. So use your own judgement.</p> +<p>A formal definition of the language can be found in <a href="rscript_abnf.html">RainerScript ABNF</a>. The +rest of this document describes the language from the user's point of +view. Please note that this doc is also currently under development and +can (and will) probably improve as time progresses. If you have +questions, use the rsyslog forum. Feedback is also always welcome.</p> +<h2>Data Types</h2> +RainerScript is a typeless language. That doesn't imply you don't need +to care about types. Of course, expressions like "A" + "B" will not +return a valid result, as you can't really add two letters (to +concatenate them, use the concatenation operator &). + However, all type conversions are automatically done by the +script interpreter when there is need to do so.<br> +<h2>Expressions</h2> +The language supports arbitrary complex expressions. All usual +operators are supported. The precedence of operations is as follows +(with operations being higher in the list being carried out before +those lower in the list, e.g. multiplications are done before additions.<br> +<ul> +<li>expressions in parenthesis</li><li>not, unary minus</li><li>*, /, % (modulus, as in C)</li><li>+, -, & (string concatenation)</li><li>==, !=, <>, <, >, <=, >=, contains (strings!), startswith (strings!)</li><li>and</li><li>or</li> +</ul>For example, "not a == b" probably returns not what you intended. +The script processor will first evaluate "not a" and then compare the +resulting boolean to the value of b. What you probably intended to do +is "not (a == b)". And if you just want to test for inequality, we +highly suggest to use "!=" or "<>". Both are exactly the same and +are provided so that you can pick whichever you like best. So inquality +of a and b should be tested as "a <> b". The "not" operator +should be reserved to cases where it actually is needed to form a +complex boolean expression. In those cases, parenthesis are highly +recommended. +<p>[<a href="rsyslog_conf.html">rsyslog.conf overview</a>] [<a href="manual.html">manual index</a>] [<a href="http://www.rsyslog.com/">rsyslog site</a>]</p> <p><font size="2">This documentation is part of the <a href="http://www.rsyslog.com/">rsyslog</a> |