Completion of error handling

[elfring]

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

• sigaction ⇒ Master::setupSignal
• write ⇒ Log::write

[elfring]

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

[scgywx]

thanks for your suggest.
Master::setupSignal add return value is okay.
but Log::write add the return value will no meaning,because cannot terminal programa when write return -1.

Also,Redis and Nginx source code did not do that.

[elfring]

How do you think about to improve static source code analysis also for your software?