assert_perror - test errnum and abort
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
No value is returned.
For an explanation of the terms used in this section, see attributes(7).
This is a GNU extension.
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.
This page is part of release 5.07 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/.