The Open Group Base Specifications Issue 7, 2018 edition
IEEE Std 1003.1-2017 (Revision of IEEE Std 1003.1-2008)
Copyright © 2001-2018 IEEE and The Open Group


abort - generate an abnormal process abort


#include <stdlib.h>

void abort(void);


[CX] [Option Start] 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.1-2017 defers to the ISO C standard. [Option End]

The abort() function shall cause abnormal process termination to occur, unless the signal SIGABRT is being caught and the signal handler does not return.

[CX] [Option Start] The abnormal termination processing shall include the default actions defined for SIGABRT and may include an attempt to effect fclose() on all open streams. [Option End]

The SIGABRT signal shall be sent to the calling process as if by means of raise() with the argument SIGABRT.

[CX] [Option Start] The status made available to wait(), waitid(), or waitpid() by abort() shall be that of a process terminated by the SIGABRT signal. [Option End] The abort() function shall override blocking or ignoring the SIGABRT signal.


The abort() 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 implementation-supplied functions.


The ISO/IEC 9899:1999 standard requires the abort() function to be async-signal-safe. Since POSIX.1-2017 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 fclose().''

The revised wording permits some backwards-compatibility and avoids a potential deadlock situation.

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:




exit, kill, raise, signal, wait, waitid

XBD <stdlib.h>


First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

Extensions beyond the ISO C standard are marked.

Changes are made to the DESCRIPTION for alignment with the ISO/IEC 9899:1999 standard.

The Open Group Base Resolution bwg2002-003 is applied.

IEEE Std 1003.1-2001/Cor 1-2002, item XSH/TC1/D6/10 is applied, changing the DESCRIPTION of abnormal termination processing and adding to the RATIONALE section.

IEEE Std 1003.1-2001/Cor 2-2004, item XSH/TC2/D6/9 is applied, changing ``implementation-defined functions'' to ``implementation-supplied functions'' in the APPLICATION USAGE section.

End of informative text.


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