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Standard file/word parsing problems

Shell Word Parsing
     abc  'xyz'  "def"   'a\b"c"'\ xyz\ "1'2'3\\45"   end-of\
     -line

CVS  (comma separated, quoted strings)
    "a,b",c,"d,e,\"f\",h","i,j,k"

Config files

   numerical: 99
   boolean:  True
   string: "See spot run."

XML   Containers...

    <A>
      <B OPT="hsjkd" \>
      <C>xyzzy</C>
    </A>

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See
  man 3 wordexp

Though this also performs filename globbing and comamnd substitution as well.
As such it may be considered overkill for most situations.

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CVS

This is reasonably defined and the more common problem.
And for simple uncomplicated input works well, but when you start
getting quoted strings containg commas, and then escapes quotes it
all quickly decends into madness!

But before trying to parse it...
  Stop Rolling Your Own CSV Parser!
    http://secretgeek.net/csv_trouble.asp

Psuedo code...

  Loop on the string letter by letter.
    If current_letter == quote : 
        toggle inside_quote variable.
    Else if (current_letter ==comma and not inside_quote) : 
        push current_word into array and clear current_word.
    Else 
        append the current_letter to current_word
  When the loop is done push the current_word into array

From Stack Overflow
    http://stackoverflow.com/questions/6209/

Also look at
  http://www.codeproject.com/KB/recipes/qstringparser_net.aspx

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Config files.

Like CVS it starts reasonably simply but then decends into chaos,
as more types and specifications becomes involved

The phpMyAdmin, and GDM config is probably one of the best examples.

   [main]
   numerical: 99
   boolean:  True

   [daemon]
   string: "See spot run."
   List:  "Tom", "Dick", "Harry"
   Item[1]: Apples
   Item[2]: Oranges
   Item[3]: Pears

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XML

Originally developed from HTML parsing efforts.
Extremely well defined, lots of libraries.

Generates a heirachal tree than you can follow and read.

But it is very verbose, and horrible to edit.

XML C library:  expat

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