Section: Linux Programmer's Manual (3)
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assert - abort the program if assertion is false
void assert(scalar expression);
This macro can help programmers find bugs in their programs,
or handle exceptional cases
via a crash that will produce limited debugging output.
is false (i.e., compares equal to zero),
prints an error message to standard error
and terminates the program by calling
The error message includes the name of the file and function containing the
call, the source code line number of the call, and the text of the argument;
prog: some_file.c:16: some_func: Assertion `val == 0' failed.
If the macro
is defined at the moment
was last included, the macro
generates no code, and hence does nothing at all.
It is not recommended to define
to detect error conditions since the software
may behave non-deterministically.
No value is returned.
For an explanation of the terms used in this section, see
POSIX.1-2001, POSIX.1-2008, C89, C99.
is required to be of type
and undefined behavior results if it is not, but in C99
it may have any scalar type.
is implemented as a macro; if the expression tested has side-effects,
program behavior will be different depending on whether
This may create Heisenbugs which go away when debugging
is turned on.
This page is part of release 4.16 of the Linux
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