09-11-2013
It is almost always illogical to continue after not finding a data file. What are you planning to do? Make up defaults - like setting defaults in the absence of data.
A lot of applications will ignore the absence of/or an empty config file, but the application has reasonable defaults defined. This kind of thing- checking defaults - is done when the program starts.
If you are having issues with a long-running program aborting on file not found, consider using a system call like access() to enumerate all required file resources when the program starts. Instead of running for 5 minutes, then aborting.
You do not have to open a file to see if you can read or write to it.
You simply cannot process application data from a file if it is not there. Or permissions are wrong. Or because you don't want a 3:00am telephone call. The program has to abort. Period.
Other kinds of resources may go offline - like a tape drive - then be brought back online or mounted with the correct tape. You can, again, at the get-go enumerate resources, then tell the person running the report to mount the right tape.
For report programs, a huge percent of the lines of code often deal with checking parameters and resources, getting usernames and passwords, etc. The other 10% or so actually processes data. You have to do a ton of upfront work before trying to run the actual report code. This is true for lots of different kinds of apps.
The way your question is stated it is not clear.
Last edited by jim mcnamara; 09-11-2013 at 06:58 AM..
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