.TH ASSERT 3 "$Revision$"
.ad
.SH NAME
assert \- program verification
.SH SYNOPSIS
.B #include <assert.h>
.PP
.B assert(expression)
.PP
.B _BadAssertion(fn, lino, ass)
.br
char *fn, *ass;
.br
unsigned int lino;
.SH DESCRIPTION
.PP
.I Assert
is a macro that indicates
.I expression
is expected to be true at this point in the program.
It causes a call to 
.I _BadAssertion
when 
.I expression
is false (0).
.PP
The routine
.I_BadAssertion
accepts three parameters:
a filename, a linenumber,
and a string representing a failed assertion.
It causes a
.IR sys_stop (S_ABORT)
with a diagnostic comment on standard error.
.PP
The assertions are disabled by defining the preprocessor constant NDEBUG.
.SH DIAGNOSTICS
.IR fn ,
line
.IR lino :
assertion
.I ass
failed.
.br
.I fn
is the source file,
.I lino
is the source line number,
and
.I ass
is the assertion
of the
.I assert
statement.
.SH MODULES
system(3)
.SH FILES
.nf
~em/modules/h/assert.h
~em/modules/lib/libassert.a
.fi