This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding Linux
manual page for details of Linux behavior), or the interface may not be
implemented on Linux.
abort — generate an abnormal process abort
The functionality described on this reference page is aligned with the
ISO C standard. Any conflict between the requirements described here
and the ISO C standard is unintentional. This volume of
POSIX.1‐2008 defers to the ISO C standard.
() function shall cause abnormal process termination to occur,
unless the signal SIGABRT is being caught and the signal handler does not
The abnormal termination processing shall include the default actions defined
for SIGABRT and may include an attempt to effect fclose
() on all open
The SIGABRT signal shall be sent to the calling process as if by means of
() with the argument SIGABRT.
The status made available to wait
(), or waitpid
() shall be that of a process terminated by the SIGABRT signal.
() function shall override blocking or ignoring the SIGABRT
() function shall not return.
No errors are defined.
The following sections are informative.
Catching the signal is intended to provide the application developer with a
portable means to abort processing, free from possible interference from any
The ISO/IEC 9899:1999 standard requires the abort
() function to be
async-signal-safe. Since POSIX.1‐2008 defers to the ISO C
standard, this required a change to the DESCRIPTION from ``shall include the
effect of fclose
()'' to ``may include an attempt to effect
The revised wording permits some backwards-compatibility and avoids a potential
The Open Group Base Resolution bwg2002‐003 is applied, removing the
following XSI shaded paragraph from the DESCRIPTION:
``On XSI-conformant systems, in addition the abnormal termination processing
shall include the effect of fclose
() on message catalog descriptors.''
There were several reasons to remove this paragraph:
- No special processing of open message catalogs needs to be
performed prior to abnormal process termination.
- The main reason to specifically mention that abort()
includes the effect of fclose() on open streams is to flush output
queued on the stream. Message catalogs in this context are read-only and,
therefore, do not need to be flushed.
- The effect of fclose() on a message catalog
descriptor is unspecified. Message catalog descriptors are allowed, but
not required to be implemented using a file descriptor, but there is no
mention in POSIX.1‐2008 of a message catalog descriptor using a
standard I/O stream FILE object as would be expected by
The Base Definitions volume of POSIX.1‐2008,
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2013 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
7, Copyright (C) 2013 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013
Technical Corrigendum 1 applied.) In the event of any discrepancy between this
version and the original IEEE and The Open Group Standard, the original IEEE
and The Open Group Standard is the referee document. The original Standard can
be obtained online at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are most likely
to have been introduced during the conversion of the source files to man page
format. To report such errors, see