HXPIPE(1)							  HTML-XML-utils							 HXPIPE(1)

NAME

       hxpipe - convert XML file to a format easier to parse with Perl or AWK

SYNOPSIS

       hxpipe [ -l ] [ -- ] [ file-or-URL ]

DESCRIPTION

       hxpipe  parses  an  HTML or XML file and outputs a line-oriented representation of it that is well suited to further processing with AWK or
       similar tools. The format is similar to the ESIS (Element Structure Information Set) that is output by nsgmls/onsgmls.

       The reverse operation, converting back to mark-up, is performed by the hxunpipe program.

       The output format is as follows:

       <!--comment-->
		 Comments are output as

		     *comment

		 I.e., a single line starting with "*" followed by the text of the comment. Line feeds, carriage returns and tabs in the text  are
		 written  as "
", "
" and "	", respectively. Text that looks like a numerical character entity is written with the "&" replaced
		 by "".  The line ends with a line feed.

		 Note that onsgmls outputs comments starting with a "_" instead of a "*" and doesn't replace the "&" of numerical character  enti-
		 ties by "" (and by default it omits comments altogether).

       <?processing instruction>
		 Processing instructions are output as

		     ?processing instruction

		 I.e.,	a  single line starting with a "?" followed by the text of the processing instruction. The text is escaped as for comments
		 (see above).

       <!DOCTYPE root PUBLIC "-//foo//DTD bar//EN" "http://example.org/dtd">
		 DOCTYPEs are output as one of the following:

		     !root "-//foo//DTD bar//EN" http://example.org/dtd
		     !root "-//foo//DTD bar//EN"
		     !root "" http://example.org/dtd
		     !root ""

		 for respectively: a DOCTYPE with (1) both a public and a system identifier, (2) only a public identifier, (3) only a system iden-
		 tifier,  or  (4)  neither  of	the  two. I.e., a single line starting with a "!", followed by a space and a possibly empty quoted
		 string, followed optionally by a space and arbitrary text. Note the quotes for the public identifier and the  absence	of  quotes
		 for the system identifier.

       <elt att1="value1" att2="value2">
		 A start tag is output as

		     Aatt1 CDATA value1
		     Aatt2 CDATA value2
		     (elt

		 I.e., as zero or more lines for the attributes and one line for the element type. Each line for an attribute starts with "A" fol-
		 lowed by the name of the attribute, a space, the literal string "CDATA", another space, and the attribute value. The text of  the
		 attribute  value  is  escaped	as for comments (see above). The line for the element type starts with "(" followed by the element
		 type.

		 hxpipe does not read DTDs and assumes that attributes are always CDATA. It never  generates  other  types  (IMPLIED,  TOKEN,  ID,
		 etc.), unlike onsgmls.

       </elt>	 End tags are output as

		     )elt

		 I.e., as a line starting with ")" followed by the element type.

       <empty att1="val1" att2="val2"/>
		 Empty elements (in XML) are output as

		     Aatt1 CDATA val1
		     Aatt2 CDATA val2
		     |empty

		 I.e., as zero or more lines for attributes and one line starting with "|" followed by the element type.

		 Note  that  onsgmls  never  outputs "|". (However, it can optionally output a line consisting of a single "e" just before the "("
		 line, to indicate that the element is empty.)

       text	 Text is output as

		     -text

		 I.e., as a single line starting with a "-". The text is escaped as for comments (see above).

       line numbers
		 When the -l option is in effect, hxpipe will intersperse the output with lines of the form

		     L12

		 where "12" is replaced with the line number in the source where the next output came from.

       hxpipe does not normalize the input and does not add mising tags. It is thus possible that there are unequal numbers of "(" and ")"  lines.
       If it is important that every start tag is matched by an end tag, pipe the input through hxnormalize -x first.

OPTIONS

       The following options are supported:

       -l	 Add "L" lines to the output to indicate the line numbers in the source.

OPERANDS

       The following operand is supported:

       file-or-URL
		 The name or URL of an HTML file. If absent, standard input is read instead.

EXIT STATUS

       The following exit values are returned:

       0	 Successful completion.

       > 0	 An error occurred in the parsing of the HTML file.  hxpipe will try to correct the error and produce output anyway.

ENVIRONMENT

       To use a proxy to retrieve remote files, set the environment variables http_proxy and ftp_proxy.  E.g., http_proxy="http://localhost:8080/"

BUGS

       The  error  recovery  for  incorrect  HTML is primitive.  hxnormalize can currently only retrieve remote files over HTTP. It doesn't handle
       password-protected files, nor files whose content depends on HTTP "cookies."

SEE ALSO

       hxunpipe(1), onsgmls(1).

6.x								    10 Jul 2011 							 HXPIPE(1)