Completion of error handling

[elfring]

Describe the bug

Would you like to add more error handling for return values from functions like the following?

• fclose ⇒ extractFile
• malloc ⇒ RpcOut_Construct
• printf ⇒ printMode

Reproduction steps

Source code review

Expected behavior

💭 I suggest to avoid ignorance of return values a bit more.
Would you like to detect every error situation as early as possible?

Additional context

• 🤔 How do you think about to improve static source code analysis also for this software?
• 🔮 How will chances evolve to benefit any more also from the means of aspect-oriented software development?