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| author | Rainer Gerhards <rgerhards@adiscon.com> | 2008-02-28 10:40:34 +0000 |
|---|---|---|
| committer | Rainer Gerhards <rgerhards@adiscon.com> | 2008-02-28 10:40:34 +0000 |
| commit | b8455132707ab4e5ca86e320c5cd8f8b84d6fc34 (patch) | |
| tree | d5c86299463ca9d2f35bedaa52aef72a22ac14f3 /doc/rscript_abnf.html | |
| parent | 8860335f57904501bfd72c1c5b65b0c83c7d1c1e (diff) | |
| download | rsyslog-b8455132707ab4e5ca86e320c5cd8f8b84d6fc34.tar.gz rsyslog-b8455132707ab4e5ca86e320c5cd8f8b84d6fc34.tar.xz rsyslog-b8455132707ab4e5ca86e320c5cd8f8b84d6fc34.zip | |
- wrote doc on how to use the expression engine
- changed ABNF to fully support old property names
- added case-insensitive comparison operations
Diffstat (limited to 'doc/rscript_abnf.html')
| -rw-r--r-- | doc/rscript_abnf.html | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/doc/rscript_abnf.html b/doc/rscript_abnf.html index 6ffd4c37..97de7284 100644 --- a/doc/rscript_abnf.html +++ b/doc/rscript_abnf.html @@ -1,8 +1,6 @@ <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html><head> -<meta http-equiv="Content-Language" content="en"><title>RainerScript ABNF</title> - -</head> +<meta http-equiv="Content-Language" content="en"><title>RainerScript ABNF</title></head> <body> <h1>RainerScript ABNF</h1> <p>This is the formal definition of RainerScript, as supported by @@ -23,7 +21,7 @@ and many other languages).</p> <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 := "$" name<br>name := alpha *(alnum)<br>constant := string / number<br>string := simpstr / tplstr ; tplstr will be implemented in next phase<br>simpstr := "'" *char "'" ; use your imagination for char ;)<br>tplstr := '"' template '"' ; not initially implemented<br>number := ["-"] 1*digit ; 0nn = octal, 0xnn = hex, nn = decimal<br>cmp_op := "==" / "!=" / "<>" / "<" / ">" / "<=" / ">=" / "contains" / "startswith"<br>digit := %x30-39<br>alpha := "a" ... "z" # all letters<br>alnum :* alpha / digit / "_"<br></pre> +<pre>; <span style="font-weight: bold;">all of this is a working document and may change!</span> -- rgerhards, 2008-02-24<br><br>script := *stmt<br>stmt := (if_stmt / block / vardef / run_s / load_s)<br>vardef := "var" ["scope" = ("global" / "event")] <br>block := "begin" stmt "end"<br>load_s := "load" constraint ("module") modpath params ; load mod only if expr is true<br>run_s := "run" constraint ("input") name<br>constraint:= "if" expr ; constrains some one-time commands<br>modpath := expr<br>params := ["params" *1param *("," param) "endparams"]<br>param := paramname) "=" expr<br>paramname := [*(obqualifier ".") name]<br>modpath:= ; path to module<br>?line? := cfsysline / cfli<br>cfsysline:= BOL "$" *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" / "contains_i" / "startswith" / "startswith_i"<br>digit := %x30-39<br>alpha := "a" ... "z" # all letters<br>alnum :* alpha / digit / "_" /"-" # "-" necessary to cover currently-existing message properties<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 |