Saving text file as read-only

[Brian Yennie]

Bruce,

A couple of suggestions:

1) Include a checksum in the file of it's contents- if the checksum 
doesn't match the file contents then you know that someone modified the 
file. See md5() function to generate a unique value based on the 
contents of the file. Unless you students know how to update the 
checksum, you should be safe.

2) If you are on an operating system with user/group permissions you 
can manipulate, grant ownership of the files to a super-user, and 
read-only permission to others. On MacOS X, for example, you can do 
something like:

sudo chown admin myfile.txt
chmod +r myfile.txt

Using shell().

HTH,
Brian

> I want to save student records from a little grammar program in a text 
> file, but I don't want the students to improve their results!!
>
> I can do a simple encryption with
>
> put numToChar(charToNum(char x of cd fld "data")+20) after holdit
>
> but a better way would be to save the text file as read only. I can't 
> find any way to do that. Can anyone help?