Completion of error handling

[elfring]

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

• malloc ⇒ node_pair_new
• fputs ⇒ print_id

[matz]

we welcome pull requests to fix those rough edges.

[elfring]

I suggest to avoid ignorance of return values a bit more.

Are you interested to apply aspect-oriented software development?
How do you think about to encapsulate error detection and corresponding exception handling as a reusable aspect in your software?