xmlsimple - add facilities for writing simple one-line scripts with the gawk-xml extension, and also simplify writing more complex scripts.
@include "xmlsimple"
parentpath =
XmlParent(path)
test = XmlMatch(path)
scopepath = XmlMatchScope(path)
ancestorpath = XmlMatchAttr(path, name, value, mode)
XmlGrep()
The xmlsimple library facilitates writing simple one-line scripts based on the gawk-xml extension. Also provides higher-level functions that simplify writing more complex scripts. It is an alternative to the xmllib library. A key difference is that $0 is not changed, so xmlsimple is compatible with awk code that relies on the gawk-xml core interface.
Short token
variable names
To shorten simple scripts, xmlsimple provides
two-letter named variables that duplicate predefined
token-related core variables:
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XD |
Equivalent to XMLDECLARATION. |
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SD |
Equivalent to XMLSTARTDOCT. |
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ED |
Equivalent to XMLENDDOCT. |
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PI |
Equivalent to XMLPROCINST. |
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SE |
Equivalent to XMLSTARTELEM. |
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EE |
Equivalent to XMLENDELEM. |
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TX |
Equivalent to XMLCHARDATA. |
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SC |
Equivalent to XMLSTARTCDATA. |
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EC |
Equivalent to XMLENDCDATA. |
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CM |
Equivalent to XMLCOMMENT. |
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UP |
Equivalent to XMLUNPARSED. |
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EOI |
Equivalent to XMLENDDOCUMENT. |
Collecting
character data
Character data items between element tags are automatically
collected in a single CHARDATA variable. This feature
simplifies processing text data interspersed with comments,
processing instructions or CDATA markup.
CHARDATA
Available at every XMLSTARTELEMENT or XMLENDELEMENT token. Contains all the character data since the previous start- or end-element tag.
Whitespace
handling
The XMLTRIM mode variable controls whether whitespace
in the CHARDATA variable is automatically trimmed or
not. Possible values are:
XMLTRIM = 0
Keep all whitespace
XMLTRIM = 1 (default)
Discard leading and trailing whitespace, and collapse contiguous whitespace characters into a single space char.
XMLTRIM = -1
Just collapse contiguous whitespace characters into a single space char. Keeps the collapsed leading or trailing whitespace.
Record
ancestors information
The ATTR array variable automatically keeps the
attributes of every ancestor of the current element, and of
the element itself.
ATTR[path@attribute]
Contains the value of the specified attribute of the ancestor element at the given path.
Example
While processing a /books/book/title element, ATTR["/books/book@on-loan"] contains the name of the book loaner.
Path related
functions
A fixed path is a slash delimited list of direct child
elements (/name/name/...). A path expression accepts also an
asterisk (*) to match any name, and a double slash (//) to
represent a descendant at any level. An absolute path starts
with a slash (path from the root element). A relative path
without a leading slash can start at any level (path from
some ancestor).
XmlParent(path)
Returns the path of the parent element. I.e., the path argument without the last /name part. The path argument is optional. If not given the XMLPATH is used.
XmlMatch(path)
Tests whether the current XMLPATH matches the path expression argument, anchored at the end.
XmlMatchScope(path)
Returns the XMLPATH prefix not matched by the matching path expression argument. Returns a null value if there is no match.
XmlMatchAttr(path, name, value, mode)
Returns the path of the innermost ancestor that matches the path argument and also has a name attribute with the given value. The mode argument is optional. If non-null then the value is handled as a regular expression instead of a fixed value.
Grep-like
facilities
XmlGrep()
If invoked at the XMLSTARTELEM event, causes the whole element subtree to be copied to the output.
The xmlsimple library includes both the xmlbase and xmlcopy libraries. Their functionality is implicitly available.
The path related functions only operate on elements. Comments, processing instructions or CDATA sections are not taken into account.
XmlGrep() cannot be used to copy tokens outside the root element (XML prologue or epilogue).
XML Processing With gawk, xmlbase(3am), xmlcopy(3am), xmltree(3am), xmlwrite(3am).
Manuel Collado, m-collado@users.sourceforge.net.
Copyright (C) 2017, Free Software Foundation, Inc.
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