From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Russ Cox" <rsc@plan9.bell-labs.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] plan9 program to balance your checking account
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Date: Sat,  3 Mar 2001 02:06:59 -0500
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The C program admittedly does more than this,
but I've been quite happy with:

g% cat balance.awk
/^#/	{ next; }
NF>=3 && $1 == "+" { total += $3; next; }
NF>=3 && $1 == "-" { total -= $3; next; }
NF>=3 && $1 ~ /^[0-9]+$/ { total -= $3; next; }
NF>=3 && $1 == "=" {
	n = total - $3;	
	if(n < -0.005 || 0.005 < n)
		printf("%s:%d: computed total %.2f expected %.2f\n",
			FILENAME, NR, total, $3);
	next;
}
{ printf("%s:%d: syntax error: %s\n", FILENAME, NR, $0); }

END{ print total }
g%

The input file is a sequence of lines of the form
	+|-|=|checknumber	mm/dd/yyyy	amount	comment

Russ