Checking .txt file with valid XML tags

Question

hey guys,
I've a .txt file which conatins info with XML tags. I've to check whether the file contains valid tags or not!
a tag should start with "<" and end with ">", there shouldn't be space between characters after "<" e.g.
a tag should be like "<name>" or "</name>" not "< name>" or  "< /name>" nor "<name" or "</name"nor "name>" or  "/name>"Here is an example of a well formed XML document:
<root>
Some text <nextTag> more text  <secondTag> stuff </secondTag> </nextTag> more text again
</root>Here is an example of XML .txt file:
<students >
     <student>
          <name> John </name>
          <name> Doe </name>
          <address> 98 Pine St.</address>
     </stdnt>
</students>I also have to make sure that no text appears before and after the root tag! Please help me, i'm trying to figure out but my alogrithm just doesn't work! Thanks in advance!!!

Answer 1

What's the purpose of those requirements? If you
wanted to check whether the file was well-formed XML
then you would just need to run it through an XML
parser. But some of the things you plan to reject are
actually well-formed XML. I don't see the point of
that.basically, it's my assignment. In the assignment our task is to check the .txt files to make sure that all XML tags are valid. The problems i mentioned in my first post, i've figured those out, eventually. There're few other things which i've to also make sure for example no text appearing before and after the root tag
Can someone please tell me how i can check following cases:
text<root> or </root> text  (both are invalid XML files)