i want create alerts for logs..so what are the languages does splunk supports for writing scripts
Splunk supports a variety of languages. Try taking a look at some of the documentation pertaining to scripted inputs, modular inputs, and sdks.
http://docs.splunk.com/Documentation/Splunk/latest/AdvancedDev/ScriptedInputsIntro
http://docs.splunk.com/Documentation/Splunk/6.5.2/Data/Getdatafromscriptedinputs
http://docs.splunk.com/Documentation/Splunk/6.5.2/AdvancedDev/ModInputsIntro
http://dev.splunk.com/sdks