This function parses INI file FileName and returns it as a structure with section names and keys as fields.

Sections from INI file are returned as fields of INI structure. Each fiels (section of INI file) in turn is structure. It's fields are variables from the corresponding section of the INI file.

If INI file contains "oprhan" variables at the beginning, they will be added as fields to INI structure.

Lines starting with ';' and '#' are ignored (comments).

See example below for more information.

Usually, INI files allow to put spaces and numbers in section names without restrictions as long as section name is between '[' and ']'. It makes people crazy to convert them to valid Matlab variables. For this purpose Matlab provides GENVARNAME function, which does
"Construct a valid MATLAB variable name from a given candidate".
See 'help genvarname' for more information.

The INI2STRUCT function uses the GENVARNAME to convert strange INI file string into valid Matlab field names.

[ test.ini ]~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SectionlessVar1=Oops
SectionlessVar2=I did it again ;o)
[Application]
Title = Cool program
LastDir = c:\Far\Far\Away
NumberOFSections = 2
[1st section]
param1 = val1
Param 2 = Val 2
[Section #2]
param1 = val1
Param 2 = Val 2

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The function converts this INI file it to the following structure:

[ MatLab session (R2006b) ]~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> INI = ini2struct('test.ini');
>> disp(INI)
sectionlessvar1: 'Oops'
sectionlessvar2: 'I did it again ;o)'
application: [1x1 struct]
x1stSection: [1x1 struct]
section0x232: [1x1 struct]

>> disp(INI.application)
title: 'Cool program'
lastdir: 'c:\Far\Far\Away'
numberofsections: '2'

>> disp(INI.x1stSection)
param1: 'val1'
param2: 'Val 2'

>> disp(INI.section0x232)
param1: 'val1'
param2: 'Val 2'
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

NOTE.
WhatToDoWithMyVeryCoolSectionAndVariableNamesInIniFileMyVeryCoolProgramWrites?
GENVARNAME also does the following:
"Any string that exceeds NAMELENGTHMAX is truncated". (doc genvarname)