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diff --git a/man/man3/assert.3 b/man/man3/assert.3 new file mode 100644 index 000000000..daec8d92b --- /dev/null +++ b/man/man3/assert.3 @@ -0,0 +1,96 @@ +'\" t +.\" Copyright (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de) +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" Modified Sat Jul 24 21:42:42 1993 by Rik Faith <faith@cs.unc.edu> +.\" Modified Tue Oct 22 23:44:11 1996 by Eric S. Raymond <esr@thyrsus.com> +.\" Modified Thu Jun 2 23:44:11 2016 by Nikos Mavrogiannopoulos <nmav@redhat.com> +.TH assert 3 (date) "Linux man-pages (unreleased)" +.SH NAME +assert \- abort the program if assertion is false +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <assert.h> +.P +.BI "void assert(scalar " expression ); +.fi +.SH DESCRIPTION +This macro can help programmers find bugs in their programs, +or handle exceptional cases +via a crash that will produce limited debugging output. +.P +If +.I expression +is false (i.e., compares equal to zero), +.BR assert () +prints an error message to standard error +and terminates the program by calling +.BR abort (3). +The error message includes the name of the file and function containing the +.BR assert () +call, the source code line number of the call, and the text of the argument; +something like: +.P +.in +4n +.EX +prog: some_file.c:16: some_func: Assertion \`val == 0\[aq] failed. +.EE +.in +.P +If the macro +.B NDEBUG +is defined at the moment +.I <assert.h> +was last included, the macro +.BR assert () +generates no code, and hence does nothing at all. +It is not recommended to define +.B NDEBUG +if using +.BR assert () +to detect error conditions since the software +may behave non-deterministically. +.SH RETURN VALUE +No value is returned. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR assert () +T} Thread safety MT-Safe +.TE +.SH STANDARDS +C11, POSIX.1-2008. +.SH HISTORY +C89, C99, POSIX.1-2001. +.P +In C89, +.I expression +is required to be of type +.I int +and undefined behavior results if it is not, but in C99 +it may have any scalar type. +.\" See Defect Report 107 for more details. +.SH BUGS +.BR assert () +is implemented as a macro; if the expression tested has side-effects, +program behavior will be different depending on whether +.B NDEBUG +is defined. +This may create Heisenbugs which go away when debugging +is turned on. +.SH SEE ALSO +.BR abort (3), +.BR assert_perror (3), +.BR exit (3) |