conditional

XMLIF(1)																  XMLIF(1)

NAME

       xmlif - conditional processing instructions for XML

SYNOPSIS

       xmlif [attrib=value...]

DESCRIPTION

       xmlif  filters  XML  according  to  conditionalizing  markup.  This can be useful for formatting one of several versions of an XML document
       depending on conditions passed to the command.

       Attribute/value pairs from the command line are matched against the attributes associated with certain processing instructions in the docu-
       ment. The instructions are <?if> and its inverse <?if not>, <?elif> and its inverse <?elif not>, <?else>, and <?fi>.

       Argument/value  pairs  given  on  the  command line are checked against the value of corresponding attributes in the conditional processing
       instructions. An `attribute match' happens if an attribute occurs in both the command-line arguments and the tag, and the values match.	An
       `attribute mismatch' happens if an attribute occurs in both the command-line arguments and the tag, but the values do not match.

       Spans  between  <?if>  or <?elif> and the next conditional processing instruction at the same nesting level are passed through unaltered if
       there is at least one attribute match and no attribute mismatch; spans between <?if not> and <?elif not> and the next conditional  process-
       ing  instruction are passed otherwise. Spans between <?else> and the next conditional-processing tag are passed through only if no previous
       span at the same level has been passed through. <?if> and <?fi> (and their `not' variants) change the current nesting  level;  <?else>  and
       <?elif> do not.

       All  these  processing  instructions will be removed from the output produced. Aside from the conditionalization, all other input is passed
       through untouched; in particular, entity references are not resolved.

       Value matching is by string equality, except that "|" in an attribute value is  interpreted  as	an  alternation  character.  Thus,  saying
       foo='red|blue'  on  the	command  line enables conditions red and blue. Saying color='black|white' in a tag matches command-line conditions
       color='black' and color='white'.

       Here is an example:

       Always issue this text.
       <?if condition='html'>
       Issue this text if 'condition=html' is given on the command line.
       <?elif condition='pdf|ps'>
       Issue this text if 'condition=pdf' or 'condition=ps'
       is given on the command line.
       <?else>
       Otherwise issue this text.
       <?fi>
       Always issue this text.

FUTURE DIRECTIONS

       The mark-up used by this tool is not set in stone, and may change in the near future.

AUTHOR

       Eric S. Raymond.

								    Sep 26 2002 							  XMLIF(1)