xmlif - conditional processing instructions for XML
xmlif filters XML according to conditionalizing markup. This can be
useful for formatting one of several versions of an XML document de-
pending on conditions passed to the command.
Attribute/value pairs from the command line are matched against the at-
tributes associated with certain processing instructions in the docu-
ment. The instructions are <?xmlif if?> and its inverse <?xmlif if
not?>, <?xmlif elif?> and its inverse <?xmlif elif not?>, <?xmlif
else?>, and <?xmlif fi?>.
Argument/value pairs given on the command line are checked against the
value of corresponding attributes in the conditional processing in-
structions. An ‘attribute match’ happens if an attribute occurs in both
the command-line arguments and the tag, and the values match. An ‘at-
tribute mismatch’ happens if an attribute occurs in both the com-
mand-line arguments and the tag, but the values do not match.
Spans between <?xmlif if?> or <?xmlif elif?> and the next conditional
processing instruction at the same nesting level are passed through un-
altered if there is at least one attribute match and no attribute mis-
match; spans between <?xmlif if not?> and <?xmlif elif not?> and the
next conditional processing instruction are passed otherwise. Spans be-
tween <?xmlif else?> and the next conditional-processing tag are passed
through only if no previous span at the same level has been passed
through. <?xmlif if?> and <?xmlif fi?> (and their ‘not’ variants)
change the current nesting level; <?xmlif else?> and <?xmlif elif?> do
All these processing instructions will be removed from the output pro-
duced. 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.
<?xmlif if condition=’html’?>
Issue this text if ’condition=html’ is given on the command line.
<?xmlif elif condition=’pdf|ps’?>
Issue this text if ’condition=pdf’ or ’condition=ps’
is given on the command line.
Otherwise issue this text.
Always issue this text.
Eric S. Raymond <email@example.com>.
Eric S. Raymond.
Oct 15 2003 XMLIF(1)
Man(1) output converted with