`abort`

Article
02/07/2023

Aborts the current process and returns an error code.

Note

Do not use this method to shut down a Microsoft Store app or Universal Windows Platform (UWP) app, except in testing or debugging scenarios. Programmatic or UI ways to close a Store app are not permitted according to the Microsoft Store policies. For more information, see UWP app lifecycle.

Syntax

void abort( void );

Return value

abort doesn't return control to the calling process. By default, it checks for an abort signal handler and raises SIGABRT if one is set. Then abort terminates the current process and returns an exit code to the parent process.

Remarks

Microsoft Specific

By default, when an app is built with the debug runtime library, the abort routine displays an error message before SIGABRT is raised. For console apps running in console mode, the message is sent to STDERR. Windows desktop apps and console apps running in windowed mode display the message in a message box. To suppress the message, use _set_abort_behavior to clear the _WRITE_ABORT_MSG flag. The message displayed depends on the version of the runtime environment used. For applications built by using the most recent versions of Visual C++, the message resembles this one:

R6010 - abort() has been called

In previous versions of the C runtime library, this message was displayed:

This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information.

When the program is compiled in debug mode, the message box displays options to Abort, Retry, or Ignore. If the user chooses Abort, the program terminates immediately and returns an exit code of 3. If the user chooses Retry, a debugger is invoked for just-in-time debugging, if available. If the user chooses Ignore, abort continues normal processing.

In both retail and debug builds, abort then checks whether an abort signal handler is set. If a non-default signal handler is set, abort calls raise(SIGABRT). Use the signal function to associate an abort signal handler function with the SIGABRT signal. You can perform custom actions—for example, clean up resources or log information—and terminate the app with your own error code in the handler function. If no custom signal handler is defined, abort doesn't raise the SIGABRT signal.

By default, in non-debug builds of desktop or console apps, abort then invokes the Windows Error Reporting Service mechanism (formerly known as Dr. Watson) to report failures to Microsoft. This behavior can be enabled or disabled by calling _set_abort_behavior and setting or masking the _CALL_REPORTFAULT flag. When the flag is set, Windows displays a message box that has text something like "A problem caused the program to stop working correctly." The user can choose to invoke a debugger with a Debug button, or choose the Close program button to terminate the app with an error code that's defined by the operating system.

If the Windows error reporting handler isn't invoked, then abort calls _exit to terminate the process with exit code 3 and returns control to the parent process or the operating system. _exit doesn't flush stream buffers or do atexit/_onexit processing.

For Windows compatibility reasons, when abort calls _exit, it may invoke the Windows ExitProcess API, which in turn allows DLL termination routines to run. Destructors aren't run in the executable, but the same may not be true of DLLs loaded in the executable's process space. This behavior doesn't strictly conform to the C++ standard. To immediately terminate a process including any DLLs, use the Windows TerminateProcess API. You can also register an abort signal handler that invokes TerminateProcess for standard-compliant behavior. Compliant behavior may come at some cost in Windows compatibility.

For more information about CRT debugging, see CRT debugging techniques.

End Microsoft Specific

By default, this function's global state is scoped to the application. To change it, see Global state in the CRT.

Requirements

Routine	Required header
`abort`	`<process.h>` or `<stdlib.h>`

Example

The following program tries to open a file and aborts if the attempt fails.

// crt_abort.c
// compile with: /TC
// This program demonstrates the use of
// the abort function by attempting to open a file
// and aborts if the attempt fails.

#include  <stdio.h>
#include  <stdlib.h>

int main( void )
{
    FILE    *stream = NULL;
    errno_t err = 0;

    err = fopen_s(&stream, "NOSUCHF.ILE", "r" );
    if ((err != 0) || (stream == NULL))
    {
        perror( "File could not be opened" );
        abort();
    }
    else
    {
        fclose( stream );
    }
}

File could not be opened: No such file or directory