'\" t
.\"     Title: xmlif
.\"    Author: Eric S. Raymond <esr@snark.thyrsus.com>
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
.\"      Date: April 2009
.\"    Manual: xmlif
.\"    Source: Linux
.\"  Language: English
.\"
.TH "XMLIF" "1" "April 2009" "Linux" "xmlif"
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.SH "NAME"
xmlif \- conditional processing instructions for XML
.SH "SYNOPSIS"
.HP \w'\fBxmlif\fR\ 'u
\fBxmlif\fR [attrib=value...]
.SH "DESCRIPTION"
.PP
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\&.
.PP
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?>\&.
.PP
Argument/value pairs given on the command line are checked against the value of corresponding attributes in the conditional processing instructions\&. An `attribute match\*(Aq happens if an attribute occurs in both the command\-line arguments and the tag, and the values match\&. An `attribute mismatch\*(Aq happens if an attribute occurs in both the command\-line arguments and the tag, but the values do not match\&.
.PP
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\*(Aq variants) change the current nesting level;
<?xmlif else?>
and
<?xmlif elif?>
do not\&.
.PP
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\&.
.PP
Value matching is by string equality, except that "|" in an attribute value is interpreted as an alternation character\&. Thus, saying foo=\*(Aqred|blue\*(Aq on the command line enables conditions red and blue\&. Saying color=\*(Aqblack|white\*(Aq in a tag matches command\-line conditions color=\*(Aqblack\*(Aq and color=\*(Aqwhite\*(Aq\&.
.PP
Here is an example:
.sp
.if n \{\
.RS 4
.\}
.nf
Always issue this text\&.
<?xmlif if condition=\*(Aqhtml\*(Aq?>
Issue this text if \*(Aqcondition=html\*(Aq is given on the command line\&.
<?xmlif elif condition=\*(Aqpdf|ps\*(Aq?>
Issue this text if \*(Aqcondition=pdf\*(Aq or \*(Aqcondition=ps\*(Aq
is given on the command line\&.
<?xmlif else?>
Otherwise issue this text\&.
<?xmlif fi?>
Always issue this text\&.
.fi
.if n \{\
.RE
.\}
.SH "AUTHOR"
.PP
\fBEric S\&. Raymond\fR <\&esr@snark\&.thyrsus\&.com\&>
.RS 4
Author of xmlif program
.RE