Terminate the calling process after cleanup (exit) or immediately (_exit).
void exit(
int status
);
void _exit(
int status
);
Parameter
status
Exit status.
Remarks
The exit and _exit functions terminate the calling process. exit calls, in last-in-first-out (LIFO) order, the functions registered by atexit and _onexit, then flushes all file buffers before terminating the process. _exit terminates the process without processing atexit or _onexit or flushing stream buffers. The status value is typically set to 0 to indicate a normal exit and set to some other value to indicate an error.
Although the exit and _exit calls do not return a value, the low-order byte of status is made available to the waiting calling process, if one exists, after the calling process exits. The status value is available to the operating-system batch command ERRORLEVEL and is represented by one of two constants: EXIT_SUCCESS, which represents a value of 0, or EXIT_FAILURE, which represents a value of 1. The behavior of exit, _exit, _cexit, and _c_exit is as follows.
FunctionDescription
exitPerforms complete C library termination procedures, terminates the process, and exits with the supplied status code.
_exitPerforms quick C library termination procedures, terminates the process, and exits with the supplied status code.
_cexitPerforms complete C library termination procedures and returns to the caller, but does not terminate the process.
_c_exitPerforms quick C library termination procedures and returns to the caller, but does not terminate the process.

When you call the exit or _exit functions, the destructors for any temporary or automatic objects that exist at the time of the call are not called. An automatic object is an object that is defined in a function where the object is not declared to be static. A temporary object is an object created by the compiler. To destroy an automatic object before calling exit or _exit, explicitly call the destructor for the object, as follows:
myObject.myClass::~myClass();
You should not call exit from DllMain with DLL_PROCESS_ATTACH. If you want to exit the DLLMain function, return FALSE from DLL_PROCESS_ATTACH.
Requirements
FunctionRequired headerCompatibility
exit<process.h> or <stdlib.h>ANSI, Win 98, Win Me, Win NT, Win 2000, Win XP
_exit<process.h> or <stdlib.h>Win 98, Win Me, Win NT, Win 2000, Win XP

For additional compatibility information, see Compatibility in the Introduction.
Libraries
All versions of the C run-time libraries.
Example
// crt_exit.c
/* This program returns an exit code of 1. The
* error code could be tested in a batch file.
*/

#include <stdlib.h>

int main( void )
{
exit( 1 );
}