assert_perror(3) [opendarwin man page]

ASSERT_PERROR(3)					     Linux Programmer's Manual						  ASSERT_PERROR(3)

NAME

       assert_perror - test errnum and abort

SYNOPSIS

       #define _GNU_SOURCE	   /* See feature_test_macros(7) */
       #include <assert.h>

       void assert_perror(int errnum);

DESCRIPTION

       If  the	macro  NDEBUG  was defined at the moment <assert.h> was last included, the macro assert_perror() generates no code, and hence does
       nothing at all.	Otherwise, the macro assert_perror() prints an error message to standard error	and  terminates  the  program  by  calling
       abort(3)  if errnum is nonzero.	The message contains the filename, function name and line number of the macro call, and the output of str-
       error(errnum).

RETURN VALUE

       No value is returned.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +----------------+---------------+---------+
       |Interface	| Attribute	| Value   |
       +----------------+---------------+---------+
       |assert_perror() | Thread safety | MT-Safe |
       +----------------+---------------+---------+

CONFORMING TO

       This is a GNU extension.

BUGS

       The purpose of the assert macros is to help programmers find bugs in their programs, things that cannot happen unless there  was  a  coding
       mistake.   However,  with  system  or  library  calls the situation is rather different, and error returns can happen, and will happen, and
       should be tested for.  Not by an assert, where the test goes away when NDEBUG is defined, but by proper error  handling	code.	Never  use
       this macro.

SEE ALSO

       abort(3), assert(3), exit(3), strerror(3)

COLOPHON

       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU
								    2017-09-15							  ASSERT_PERROR(3)

ASSERT(3)                                                    Linux Programmer's Manual                                                   ASSERT(3)

NAME

       assert - abort the program if assertion is false

SYNOPSIS

       #include <assert.h>

       void assert(scalar expression);

DESCRIPTION

       This  macro  can  help programmers find bugs in their programs, or handle exceptional cases via a crash that will produce limited debugging
       output.

       If expression is false (i.e., compares equal to zero), assert() prints an error message to standard error and  terminates  the  program  by
       calling  abort(3).   The error message includes the name of the file and function containing the assert() call, the source code line number
       of the call, and the text of the argument; something like:

           prog: some_file.c:16: some_func: Assertion `val == 0' failed.

       If the macro NDEBUG is defined at the moment <assert.h> was last included, the macro assert() generates no code, and hence does nothing  at
       all.   It  is not recommended to define NDEBUG if using assert() to detect error conditions since the software may behave non-deterministi-
       cally.

RETURN VALUE

       No value is returned.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +----------+---------------+---------+
       |Interface | Attribute     | Value   |
       +----------+---------------+---------+
       |assert()  | Thread safety | MT-Safe |
       +----------+---------------+---------+

CONFORMING TO

       POSIX.1-2001, POSIX.1-2008, C89, C99.  In C89, expression is required to be of type int and undefined behavior results if it is not, but in
       C99 it may have any scalar type.

BUGS

       assert() is implemented as a macro; if the expression tested has side-effects, program behavior will be different depending on whether NDE-
       BUG is defined.  This may create Heisenbugs which go away when debugging is turned on.

SEE ALSO

       abort(3), assert_perror(3), exit(3)

COLOPHON

       This page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and  the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU                                                                 2017-09-15                                                           ASSERT(3)