'\" t
.\" Copyright 2007 (C) Michael Kerrisk <mtk.manpages@gmail.com>
.\" some parts Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.\" References consulted:
.\"     Linux libc source code
.\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
.\"     386BSD man pages
.\" Modified Sat Jul 24 21:46:21 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified Fri Aug  4 10:51:53 2000 - patch from Joseph S. Myers
.\" 2007-12-15, mtk, Mostly rewritten
.\"
.TH abort 3 2023-10-31 "Linux man-pages 6.06"
.SH NAME
abort \- cause abnormal process termination
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.B #include <stdlib.h>
.P
.B [[noreturn]] void abort(void);
.fi
.SH DESCRIPTION
The
.BR abort ()
function first unblocks the
.B SIGABRT
signal, and then raises that signal for the calling process
(as though
.BR raise (3)
was called).
This results in the abnormal termination of the process unless the
.B SIGABRT
signal is caught and the signal handler does not return
(see
.BR longjmp (3)).
.P
If the
.B SIGABRT
signal is ignored, or caught by a handler that returns, the
.BR abort ()
function will still terminate the process.
It does this by restoring the default disposition for
.B SIGABRT
and then raising the signal for a second time.
.P
As with other cases of abnormal termination the functions registered with
.BR atexit (3)
and
.BR on_exit (3)
are not called.
.SH RETURN VALUE
The
.BR abort ()
function never returns.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.na
.nh
.BR abort ()
T}	Thread safety	MT-Safe
.TE
.SH STANDARDS
C11, POSIX.1-2008.
.SH HISTORY
SVr4, POSIX.1-2001, 4.3BSD, C89.
.P
Up until glibc 2.26,
if the
.BR abort ()
function caused process termination,
all open streams were closed and flushed (as with
.BR fclose (3)).
However, in some cases this could result in deadlocks and data corruption.
Therefore, starting with glibc 2.27,
.\" glibc commit 91e7cf982d0104f0e71770f5ae8e3faf352dea9f
.BR abort ()
terminates the process without flushing streams.
POSIX.1 permits either possible behavior, saying that
.BR abort ()
"may include an attempt to effect fclose() on all open streams".
.SH SEE ALSO
.BR gdb (1),
.BR sigaction (2),
.BR assert (3),
.BR exit (3),
.BR longjmp (3),
.BR raise (3)