RE: Two reade loops: which one preferred ?

Key chain file
Dow not %eof
   ...do whatever
Key reade file
Enddo

while ((fscanf(outfile, "%c", &c))!=EOF)
{
   do stuff...
}

In this case, you've removed a read, but complicated the code with multiple
exit conditions. In this code:

Key setll file
Key Reade file
Dow not %eof
...process record...
Key reade file
Enddo

There is an additional read, but only one exit condition (and exit condition
check). The loop is executed 0 or more times.

In your example, you must code two exit conditions because of the DOU. The
code is executed 1 or more times.

Like Jon said, a priming read determines if there is any data in the file to
process. With DOW, we know immediately whether we should continue processing
the file. With the DOU, we don't know if there's data to process until we're
in the loop; hence, two exit conditions.

Loyd Goodbar