Progress
External Program
Interfaces
Avoiding Common HLC Errors
To ensure compatibility between your HLC functions and Progress, consider the following when writing your functions:
- An HLC library function does not always return character and decimal data as null-terminated strings. For example, the pvar parameter of the
prordc()
function contains character data without null termination. To terminate such a string with the null character, you must add it yourself.- When you check the value of a field or variable that HLC returns, check for the unknown value (?). The field might not always contain a valid value.
- If you return from your top-level function without setting an appropriate return code value, Progress might raise an error condition unexpectedly. See the "Returning Error Codes From a Top-level Function" section for more information.
- Use the
promsgd()
HLC library function to display messages directly to the terminal. Using the standard C functionprintf()
might produce unexpected results when used to send raw data to a terminal.
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