oft_xml Module Reference

Detailed Description

Libxml2 DOM interface for OFT.

Provides a limited interface between Libxml2 and Fortran using iso_c_binding for DOM-style XML access, along with helper routines for parsing string content into typed Fortran values. Data stored in XML nodes/attributes can be either space-delimited or comma-delimited with newlines to denote 2D arrays.

Authors

Chris Hansen

Date

April 2026

Data Types
interface	oft_xml_free_doc_c
	Free an XML document previously parsed with oft_xml_load_file_c. More...
interface	oft_xml_free_ptr_c
	Free c objects, for example arrays returned by oft_xml_get_elements_c or strings returned by oft_xml_get_content_c. More...
interface	oft_xml_get_attribute_c
	Extract content from an attribute on a given xml node as a string. More...
interface	oft_xml_get_content_c
	Extract content from a given xml node as a string. More...
interface	oft_xml_get_element_c
	Retrieve a pointer to the i-th xml node with a given name inside a parent node. More...
interface	oft_xml_get_elements_c
	Retrieve pointers to all xml nodes with a given name inside a parent node. More...
interface	oft_xml_get_root_c
	Retrieve a pointer to the root element of an xmlDoc object. More...
interface	oft_xml_has_attribute_c
	Test if a given xml node has a given attribute. More...
interface	oft_xml_parse_file_c
	Parse an XML file from a given file path, returning a pointer to the corresponding xmlDoc. More...
type	xml_doc
	XML document wrapper. More...
type	xml_exception
interface	xml_get_element
	Get one or more elements by name from a parent node. More...
type	xml_node
	Libxml2 node wrapper. More...
type	xml_nodelist
	List of XML nodes. More...
interface	xml_read_attribute
	Extract content of a given type from an attribute on an XML node. More...
interface	xml_read_content
	Extract content of a given type from an XML node. More...

Functions/Subroutines
subroutine	normalize_string (content_in, content_out)
	Normalize a string by removing leading/trailing whitespace and blank/comment lines.
subroutine	oft_xml_free (doc_ptr)
	Free an XML document previously parsed with oft_xml_load.
subroutine	oft_xml_get_attr (node, attr_name, content, ierr)
	Extract content from a specified attribute on a given xml node into a Fortran string.
subroutine	parse_string_to_doubles (content, output, output_shape, ierr)
	Parse string content into a 1D array of double precision values with shape information.
subroutine	parse_string_to_integers (content, output, output_shape, ierr)
	Parse string content into a 1D array of integer values with shape information.
subroutine	parse_string_to_logicals (content, output, output_shape, ierr)
	Parse string content into a 1D array of logical values with shape information.
subroutine	tokenize_string (content, tokens, ierr)
	Find token boundaries in a string containing comma-delimited and/or newline-delimited values to be parsed into typed Fortran values.
subroutine	xml_clear_exceptions ()
	Clear messages from the exception stack.
subroutine	xml_extractdataattribute_double (node, attr_name, output, output_shape, iostat)
	Parse a single double precision value from an XML attribute's content.
subroutine	xml_extractdataattribute_double1d (node, attr_name, output, output_shape, iostat)
	Parse XML attribute content into a 1D array of double precision values.
subroutine	xml_extractdataattribute_double2d (node, attr_name, output, output_shape, iostat)
	Parse XML attribute content into a 2D array of double precision values.
subroutine	xml_extractdataattribute_int (node, attr_name, output, output_shape, iostat)
	Parse a single integer value from an XML attribute's content.
subroutine	xml_extractdataattribute_int1d (node, attr_name, output, output_shape, iostat)
	Parse XML attribute content into a 1D array of integer values.
subroutine	xml_extractdataattribute_int2d (node, attr_name, output, output_shape, iostat)
	Parse XML attribute content into a 2D array of integer values.
subroutine	xml_extractdataattribute_logical (node, attr_name, output, output_shape, iostat)
	Parse a single logical value from an XML attribute's content.
subroutine	xml_extractdataattribute_logical1d (node, attr_name, output, output_shape, iostat)
	Parse XML attribute content into a 1D array of logical values.
subroutine	xml_extractdataattribute_logical2d (node, attr_name, output, output_shape, iostat)
	Parse XML attribute content into a 2D array of logical values.
subroutine	xml_extractdataattribute_string (node, attr_name, output, iostat)
	Get content from an XML attribute as a string.
subroutine	xml_extractdatacontent_double (node, output, output_shape, iostat)
	Parse a single double precision value from an XML node's content.
subroutine	xml_extractdatacontent_double1d (node, output, output_shape, iostat)
	Parse XML content into a 1D array of double precision values.
subroutine	xml_extractdatacontent_double2d (node, output, output_shape, iostat)
	Parse XML content into a 2D array of double precision values.
subroutine	xml_extractdatacontent_int (node, output, output_shape, iostat)
	Parse XML content into a single integer value.
subroutine	xml_extractdatacontent_int1d (node, output, output_shape, iostat)
	Parse XML content into a 1D array of integer values.
subroutine	xml_extractdatacontent_int2d (node, output, output_shape, iostat)
	Parse XML content into a 2D array of integer values.
subroutine	xml_extractdatacontent_logical (node, output, output_shape, iostat)
	Parse XML content into a single logical value.
subroutine	xml_extractdatacontent_logical1d (node, output, output_shape, iostat)
	Parse XML content into a 1D array of logical values.
subroutine	xml_extractdatacontent_logical2d (node, output, output_shape, iostat)
	Parse XML content into a 2D array of logical values.
subroutine	xml_extractdatacontent_string (node, output, iostat)
	Get content from an XML node as a string.
subroutine	xml_get_content (node, content, ierr)
	Extract content from a given xml node into a Fortran string.
subroutine	xml_get_element_list (parent, name, elements, error_flag)
	Retrieve all xml nodes with a given name contained within a parent node.
subroutine	xml_get_element_single (parent, name, element, error_flag, index)
	Retrieve the i-th xml node with a given name contained within a parent node.
logical function	xml_hasattribute (node, attr_name)
	Test if a given xml node has a specified attribute.
logical function	xml_node_associated (self)
	Check if an xml_node is associated with a C object.
subroutine	xml_parsefile (filepath, doc, ierr)
	Parse an XML file.
subroutine	xml_print_exceptions ()
	Print messages from the exception stack.
subroutine	xml_set_exception (message)
	Add exception to the exception stack.

Variables
integer(i4)	xml_exception_depth = 0
	Exception stack depth (0 if no exceptions)
type(xml_exception), dimension(10)	xml_exceptions
	Stack of excepton messages.

Function/Subroutine Documentation

normalize_string()

subroutine normalize_string	(	character(len=*), intent(in)	content_in,
		character(len=:), intent(out), allocatable	content_out
	)

Normalize a string by removing leading/trailing whitespace and blank/comment lines.

Parameters

[in]	content_in	Input string
[out]	content_out	Output string

oft_xml_free()

subroutine oft_xml_free

(

type(c_ptr), intent(inout)

doc_ptr

)

Free an XML document previously parsed with oft_xml_load.

Parameters

[in,out]

doc_ptr

C pointer to xmlDoc to free

oft_xml_get_attr()

subroutine oft_xml_get_attr	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		character(len=:), intent(out), allocatable	content,
		integer(i4), intent(out)	ierr
	)

Extract content from a specified attribute on a given xml node into a Fortran string.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	content	Output string
[out]	ierr	Error flag (0 on success)

parse_string_to_doubles()

subroutine parse_string_to_doubles	(	character(len=*), intent(inout)	content,
		real(r8), dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out)	ierr
	)

Parse string content into a 1D array of double precision values with shape information.

Parameters

[in,out]	content	Input string
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	ierr	Error flag (0 on success)

parse_string_to_integers()

subroutine parse_string_to_integers	(	character(len=*), intent(inout)	content,
		integer(i4), dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out)	ierr
	)

Parse string content into a 1D array of integer values with shape information.

Parameters

[in,out]	content	Input string
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	ierr	Error flag (0 on success)

parse_string_to_logicals()

subroutine parse_string_to_logicals	(	character(len=*), intent(inout)	content,
		logical, dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out)	ierr
	)

Parse string content into a 1D array of logical values with shape information.

Supported values are:

• True: "true", ".true.", "1", "t" (case-insensitive)
• False: "false", ".false.", "0", "f" (case-insensitive)

  Parameters

  [in,out]	content	Input string
  [out]	output	Output array
  [out]	output_shape	Shape of the output array (ncols, nrows)
  [out]	ierr	Error flag (0 on success)

tokenize_string()

subroutine tokenize_string	(	character(len=*), intent(inout)	content,
		integer(i4), dimension(:,:,:), intent(out), allocatable	tokens,
		integer(i4), intent(out)	ierr
	)

Find token boundaries in a string containing comma-delimited and/or newline-delimited values to be parsed into typed Fortran values.

Parameters

[in,out]	content	Input string
[out]	tokens	String tokens as (start,end) indices for each column and row
[out]	ierr	Error flag (0 on success)

xml_clear_exceptions()

subroutine xml_clear_exceptions

Clear messages from the exception stack.

xml_extractdataattribute_double()

subroutine xml_extractdataattribute_double	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		real(r8), intent(out)	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse a single double precision value from an XML attribute's content.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output value
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_double1d()

subroutine xml_extractdataattribute_double1d	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		real(r8), dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML attribute content into a 1D array of double precision values.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_double2d()

subroutine xml_extractdataattribute_double2d	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		real(r8), dimension(:,:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML attribute content into a 2D array of double precision values.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_int()

subroutine xml_extractdataattribute_int	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		integer(i4), intent(out)	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse a single integer value from an XML attribute's content.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output value
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_int1d()

subroutine xml_extractdataattribute_int1d	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		integer(i4), dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML attribute content into a 1D array of integer values.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_int2d()

subroutine xml_extractdataattribute_int2d	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		integer(i4), dimension(:,:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML attribute content into a 2D array of integer values.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_logical()

subroutine xml_extractdataattribute_logical	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		logical, intent(out)	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse a single logical value from an XML attribute's content.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output value
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_logical1d()

subroutine xml_extractdataattribute_logical1d	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		logical, dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML attribute content into a 1D array of logical values.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_logical2d()

subroutine xml_extractdataattribute_logical2d	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		logical, dimension(:,:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML attribute content into a 2D array of logical values.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdataattribute_string()

subroutine xml_extractdataattribute_string	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name,
		character(len=:), intent(inout), allocatable	output,
		integer(i4), intent(out), optional	iostat
	)

Get content from an XML attribute as a string.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name
[in,out]	output	Output string
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_double()

subroutine xml_extractdatacontent_double	(	type(xml_node), intent(in)	node,
		real(r8), intent(out)	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse a single double precision value from an XML node's content.

Parameters

[in]	node	XML node
[out]	output	Output value
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_double1d()

subroutine xml_extractdatacontent_double1d	(	type(xml_node), intent(in)	node,
		real(r8), dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML content into a 1D array of double precision values.

Parameters

[in]	node	XML node
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_double2d()

subroutine xml_extractdatacontent_double2d	(	type(xml_node), intent(in)	node,
		real(r8), dimension(:,:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML content into a 2D array of double precision values.

Parameters

[in]	node	XML node
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_int()

subroutine xml_extractdatacontent_int	(	type(xml_node), intent(in)	node,
		integer(i4), intent(out)	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML content into a single integer value.

Parameters

[in]	node	XML node
[out]	output	Output value
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_int1d()

subroutine xml_extractdatacontent_int1d	(	type(xml_node), intent(in)	node,
		integer(i4), dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML content into a 1D array of integer values.

Parameters

[in]	node	XML node
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_int2d()

subroutine xml_extractdatacontent_int2d	(	type(xml_node), intent(in)	node,
		integer(i4), dimension(:,:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML content into a 2D array of integer values.

Parameters

[in]	node	XML node
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_logical()

subroutine xml_extractdatacontent_logical	(	type(xml_node), intent(in)	node,
		logical, intent(out)	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML content into a single logical value.

Parameters

[in]	node	XML node
[out]	output	Output value
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_logical1d()

subroutine xml_extractdatacontent_logical1d	(	type(xml_node), intent(in)	node,
		logical, dimension(:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML content into a 1D array of logical values.

Parameters

[in]	node	XML node
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_logical2d()

subroutine xml_extractdatacontent_logical2d	(	type(xml_node), intent(in)	node,
		logical, dimension(:,:), intent(out), pointer	output,
		integer(i4), dimension(2), intent(out), optional	output_shape,
		integer(i4), intent(out), optional	iostat
	)

Parse XML content into a 2D array of logical values.

Parameters

[in]	node	XML node
[out]	output	Output array
[out]	output_shape	Shape of the output array (ncols, nrows)
[out]	iostat	I/O status flag (0 on success)

xml_extractdatacontent_string()

subroutine xml_extractdatacontent_string	(	type(xml_node), intent(in)	node,
		character(len=:), intent(out), allocatable	output,
		integer(i4), intent(out), optional	iostat
	)

Get content from an XML node as a string.

Parameters

[in]	node	XML node
[out]	output	Output string
[out]	iostat	I/O status flag (0 on success)

xml_get_content()

subroutine xml_get_content	(	type(xml_node), intent(in)	node,
		character(len=:), intent(out), allocatable	content,
		integer(i4), intent(out)	ierr
	)

Extract content from a given xml node into a Fortran string.

Parameters

[in]	node	XML node
[out]	content	Output string
[out]	ierr	Error flag (0 on success)

xml_get_element_list()

subroutine xml_get_element_list	(	type(xml_node), intent(in)	parent,
		character(len=*), intent(in)	name,
		type(xml_nodelist), intent(inout)	elements,
		integer(i4), intent(out)	error_flag
	)

Retrieve all xml nodes with a given name contained within a parent node.

Parameters

[in]	parent	Parent element
[in]	name	Element name to find
[in,out]	elements	Found elements
[out]	error_flag	Error flag (0 if successful)

xml_get_element_single()

subroutine xml_get_element_single	(	type(xml_node), intent(in)	parent,
		character(len=*), intent(in)	name,
		type(xml_node), intent(out)	element,
		integer(i4), intent(out)	error_flag,
		integer(i4), intent(in), optional	index
	)

Retrieve the i-th xml node with a given name contained within a parent node.

Parameters

[in]	parent	Parent element
[in]	name	Element name to find
[out]	element	Found element
[out]	error_flag	Error flag (0 if successful)
[in]	index	Optional index, defaults to first matching element

xml_hasattribute()

logical function xml_hasattribute	(	type(xml_node), intent(in)	node,
		character(len=*), intent(in)	attr_name
	)

Test if a given xml node has a specified attribute.

Parameters

[in]	node	XML node
[in]	attr_name	Attribute name

xml_node_associated()

logical function xml_node_associated

(

class(xml_node), intent(in)

self

)

Check if an xml_node is associated with a C object.

Parameters

[in]

self

XML node

xml_parsefile()

subroutine xml_parsefile	(	character(len=*), intent(in)	filepath,
		type(xml_doc), intent(out)	doc,
		integer(i4), intent(out)	ierr
	)

Parse an XML file.

Parameters

[in]	filepath	Path to XML file
[out]	doc	XML document object
[out]	ierr	Error flag (0 on success)

xml_print_exceptions()

subroutine xml_print_exceptions

Print messages from the exception stack.

xml_set_exception()

subroutine xml_set_exception

(

character(len=*), intent(in)

message

)

Add exception to the exception stack.

Parameters

[in]

message

Exception message

Variable Documentation

xml_exception_depth

integer(i4) xml_exception_depth = 0

Exception stack depth (0 if no exceptions)

xml_exceptions

type(xml_exception), dimension(10) xml_exceptions

Stack of excepton messages.