assert_perror - test errnum and abort
void assert_perror(int errnum);
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 output and terminates the program by
calling abort() if errnum is nonzero. The message contains the filename,
function name and line number of the macro call, and the output of strerror(errnum).
No value is returned.
This is a GNU extension.
purpose of the assert macros is to help the programmer find bugs in his
program, 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.