How can a C program produce a core dump of itself without terminating?

Question

I want a C program to produce a core dump under certain circumstances. This is a program that runs in a production environment and isn't easily stopped and restarted to adjust other kinds of debugging code. Also, since it's in a production environment, I don't want to call abort(). The issues under investigation aren't easily replicated in a non-production environment. What I'd like is for the program, when it detects certain issues, to produce a core dump on its own, preferably with enough information to rename the file, and then continue.

Answer 1

void create_dump(void) {     if(!fork()) {         // Crash the app in your favorite way here         *((void*)0) = 42;     } } 

Fork the process then crash the child - it'll give you a snapshot whenever you want

Answer 2

Another way might be to use the Google Coredumper library. This creates a similar result to the fork+abort technique but plays nicer with multithreaded apps (suspends all threads for a little while before forking so that they don't make a mess in the child).

Example:

     #include <google/coredumper.h>     ...     WriteCoreDump('core.myprogram');     /* Keep going, we generated a core file,      * but we didn't crash.      */