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
document. 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
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 <?xmlif if?> or <?xmlif 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 <?xmlif if not?> and <?xmlif elif not?> and the
next conditional processing instruction are passed otherwise. Spans
between <?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 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.
<?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.
<?xmlif else?>
Otherwise issue this text.
<?xmlif fi?>
Always issue this text.
AUTHOR
Eric S. Raymond <esr@snark.thyrsus.com>
Author of xmlif program