diff options
Diffstat (limited to 'doc/rainerscript.html')
| -rw-r--r-- | doc/rainerscript.html | 110 |
1 files changed, 0 insertions, 110 deletions
diff --git a/doc/rainerscript.html b/doc/rainerscript.html deleted file mode 100644 index 7cbbfa9..0000000 --- a/doc/rainerscript.html +++ /dev/null @@ -1,110 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<html><head> -<meta http-equiv="Content-Language" content="en"><title>RainerScript</title> - -</head> -<body> -<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. -<h2>Lookup Tables</h2> -<p><a href="lookup_tables.html">Lookup tables</a> are a powerful construct -to obtain "class" information based on message content (e.g. to build -log file names for different server types, departments or remote -offices). -<h2>Functions</h2> -<p>RainerScript supports a currently quite limited set of functions: -<ul> -<li>getenv(str) - like the OS call, returns the value of the environment -variable, if it exists. Returns an empty string if it does not exist. -<li>strlen(str) - returns the length of the provided string -<li>tolower(str) - converts the provided string into lowercase -<li>cstr(expr) - converts expr to a string value -<li>cnum(expr) - converts expr to a number (integer) -<li>re_match(expr, re) - returns 1, if expr matches re, 0 otherwise -<li>re_extract(expr, re, match, submatch, no-found) - extracts -data from a string (property) via a regular expression match. -POSIX ERE regular expressions are used. The variable "match" contains -the number of the match to use. This permits to pick up more than the -first expression match. Submatch is the submatch to match (max 50 supported). -The "no-found" parameter specifies which string is to be returned in case when -the regular expression is not found. Note that match and submatch start with -zero. It currently is not possible to extract more than one submatch with -a single call. -<li>field(str, delim, matchnbr) - returns a field-based substring. str is the string -to search, delim is the delimiter and matchnbr is the match to search -for (the first match starts at 1). This works similar as the field based -property-replacer option. -Versions prior to 7.3.7 only support a single character as delimiter character. -Starting with version 7.3.7, a full string can be used as delimiter. If a single -character is being used as delimiter, delim is the numerical ascii value of the -field delimiter character (so that non-printable characters can by specified). If a -string is used as delmiter, a multi-character string (e.g. "#011") is to be -specified. Samples:<br> -set $!usr!field = field($msg, 32, 3); -- the third field, delimited by space<br> -set $!usr!field = field($msg, "#011", 3); -- the third field, delmited by "#011"<br> -Note that when a single character is specified as string [field($msg, ",", 3)] a -string-based extraction is done, which is more performance intense than the -equivalent single-character [field($msg, 44 ,3)] extraction. -<li>prifilt(constant) - mimics a traditional PRI-based filter (like "*.*" or -"mail.info"). The traditional filter string must be given as a <b>constant string</b>. -Dynamic string evaluation is not permitted (for performance reasons). -</ul> -<p>The following example can be used to build a dynamic filter based on some environment -variable: -<pre> -if $msg contains getenv('TRIGGERVAR') then /path/to/errfile -</pre> -<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> -project.<br> -Copyright © 2008-2013 by <a href="http://www.gerhards.net/rainer">Rainer Gerhards</a> and -<a href="http://www.adiscon.com/">Adiscon</a>. -Released under the GNU GPL version 3 or higher.</font></p> -</body></html> |