class_docstr: `Job Control Language (JCL)
  <http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IEA2B570/CCONTENTS>`_
  is a scripting language used on mainframe platforms to instruct the system
  on how to run a batch job or start a subsystem. It is somewhat
  comparable to MS DOS batch and Unix shell scripts.
  
  .. versionadded:: 2.1
class_docstr_tok: ["`","Job","Control","Language","(","JCL",")","<","http",":","\/\/publibz.boulder.ibm.com\/cgi-bin\/bookmgr_OS390\/BOOKS\/IEA2B570\/CCONTENTS",">","`","_","is","a","scripting","language","used","on","mainframe","platforms","to","instruct","the","system","on","how","to","run","a","batch","job","or","start","a","subsystem",".","It","is","somewhat","comparable","to","MS","DOS","batch","and","Unix","shell","scripts",".","..","versionadded",":",":","2.1"]
docstr: Recognize JCL job by header.
docstr_tok: ["Recognize","JCL","job","by","header","."]
code: def analyse_text(text):
      """
      Recognize JCL job by header.
      """
      result = 0.0
      lines = text.split("\n")
      if len(lines) > 0:
          if JclLexer._JOB_HEADER_PATTERN.match(lines[0]):
              result = 1.0
      assert 0.0 <= result <= 1.0
      return result
  
imports: import re
  from pygments.lexer import RegexLexer, include, bygroups, default, combined, words
  from pygments.token import Text, Comment, Operator, Keyword, Name, String, Number, Punctuation, Error, Whitespace, Other
  from pygments.util import get_bool_opt, get_list_opt, iteritems
label_desc: Use image node_id 1 for calling the JclLexer obj's underlying member method code with example usage: obj.analyse_text(text) and returns: result