How to avoid memory leak when user press ctrl+c under linux?

Question

In my program written with C and C++, I will new an object to fulfill the task, then delete the object.

At the moment after new object but before delete object, if the user presses ctrl+c to break the process, that will cause delete not to be called and a memory leak occurs.

What should I do to avoid this situation?

Also, if the memory was reclaimed by the OS, what about the opened files? Are they closed by the OS or should I close them manualy?

Answer 1

In a virtual-memory-based system, all memory is returned to the OS when a process is terminated, regardless of whether it was freed explicitly in the application code. The same might not be true of other resources, however, which you may want to free cleanly. In which case, you need to provide a custom signal handler for the SIGINT signal (which is received on Ctrl+C), see e.g. http://linux.die.net/man/2/sigaction.

Answer 2

Pressing CtrlC will send a SIGINT to the process, which by default does a mostly-orderly shutdown, including tearing down the memory manager and releasing all allocated heap and stack. If you need to perform other tasks then you will need to install a SIGINT handler and perform those tasks yourself.