1. File locking strategies with ex.exe and exu
Hello everyone,
I'm working on a very simple helpdesk / call tracking / trouble ticket
system with Euphoria. I'm sticking with a basic character cell interface
using graphics.e and putting platform() calls in so it will run unmodified
on either DOS32 (in a Windows DOS box) or on Linux (I'm using a very _old_
RedHat 5.1).
I store information for each "call" in two files. One file holds the core
call data (who opened the call, their phone number, email address and so
on). The other file holds a free format "comments" record so progress on
the call can be recorded.
When a new call is created I need to come up with unique file names to hold
the core call data and the call comments. Right now I just have a loop
with a counter to form a file name (e.g. call0001) and try and open the
file. If it opens it already exists so increment and try again. Once I
have file that doesn't open (and therefore doesn't exist) I open the file
for writing and it's mine.
Now I'm fully aware that this isn't full proof in a multi user situation.
If I was writing this in C on a UNIX box I'd be looking at the flock
routines. What can I do in Euphoria to ensure that I can open a file and
be sure that another person running the application at the same time
doesn't try and open the same file?
I'm thinking about using some sort of lock file that you write a random
string to, close the file, open for read, read the string back and if it
matches your 99.99% sure you have that file to yourself but it seems kludgy
and not 100%
So ideas for file locking methods for ex.exe and exu?
Over to you gurus 
Regards,
Andy Cranston.
