.TH ERROR 2
.SH NAME
errinit, noerror, error, catcherror \- local error handling utilities
.SH SYNOPSIS
.B #include <u.h>
.br
.B #include <libc.h>
.br
.B #include <error.h>
.PP
.B
void	errinit(int stack)
.br
.B
void	noerror(void)
.br
.B
void	error(char* msg, ...)
.br
.B
void	catcherror(void)
.br
.B
int	errstacksize(void)
.SH DESCRIPTION
These routiles are tools for error handling.
.IR catcherror ,
.IR noerror ,
.IR error ,
and
.IR errinit
provide exeption handling for C, in the same style of the similar routines used in
the kernel.
They can be used both with and without
the
.IR thread (2)
library.
.PP
.I Errinit
should be called before using any other. It should be called by each thread/process
using the error handling mechanism. Its argument,
indicaties the desired depth of the error stack for the calling process.
.PP
.I Catcherror
install an exception handling point.
.I Noerror
declares that there was no error catched, similar to the
.I poperror
function in the kernel.
.I Error
raises an error. If the argument is nil, the error string is unaltered. See the example.
.PP
.I Errstacksize
returns the number of recovery points kept in the error stack. Useful to
perform debug checks to see if the stack depth is what it should be.
.SH SOURCE
.B /sys/src/liberror
.SH EXAMPLE
Catch an error, and raise one.
.PP
.EX
void f(void)
{
	error("catch this!");
}

void
main(int argc, char **argv)
{
	errinit(32);
	if (catcherror()){
		sysfatal("catched: %r");
	}
	f();
	noerror();
}
.EE