Re: [9fans] scripting sam

["rob pike" <rob@plan9.bell-labs.com>]

Sam prints messages to stderr, so unlike the silly '-' argument to silence
ed, you can say
	sam -d foo >[2] /dev/null <<!
		...
	!

Here is an example of the combined power and idiocy of this approach.
The code is radically dependent on details of the HTML, which changes
about once a year, inviting me to dive back in to this enchanting world.


% cat /bin/weather
#!/bin/rc

rfork e

fn  sigint sighup sigterm{
	rm -f /tmp/w$pid
	exit 1
}

fn  sigexit{
	rm -f /tmp/w$pid
	exit ''
}

fn usage{
	echo usage:
	echo '	'weather known-name
	echo '		'known-names: '
			newark
			new york
			sf
			san fransisco
			la
			los angeles'
	echo '	'weather New_York NY
	echo '	'weather Toronto CN
	echo for a list of cities in new york, say
	echo '	' weather list NY
	exit
}

city = Newark
state = _NJ
country = US

switch($*){
case '?'
	usage
case newark local ''
	city = Newark; state = _NJ; country = US
case 'new york'
	city = New_York; state = _NY
case 'sf' 'san francisco'
	city = San_Francisco; state = _CA
case 'la' 'los angeles'
	city = Los_Angeles; state = _CA
case 'north pole'
	city = North_Pole_Nwt; state = ''; country = CN
case 'list '*
	city = list
	state = $2
case *
	if(! ~ $#* 2) usage
	city = $1
	state = $2
	switch($state){
	case AL AK AZ AR CA CO CT DE FL GA HI ID IL IN IA KS KY LA ME MD MA MI MN MS MO MT NE NV NH NJ NM NY NC ND OH OK OR PA RI SC SD TN TX UT VT VA WA DC WV WI WY PR
		state = _$state
		country = US
	case *
		country = $state
		state = ''
	}
}


if(~ $city list){
	if (! hget http://weather.yahoo.com/regional/US/^$state^.html > /tmp/w$pid) exit $status
	grep 'href="forecast' /tmp/w$pid | sed -n 's/.*forecast.//
		s/_'$state'_.*$//
		s/.*/weather & '$state'/p'
	exit
}

if (! hget http://weather.yahoo.com/forecast/^$city^$state^_^$country^_f.html > /tmp/w$pid) exit $status

#cat /tmp/w$pid
sam -d /tmp/w$pid >[2] /dev/null <<'!'
,s/&#176;/°/g
,s/&nbsp;//g
/^<title>.*\n/ {
	y!</?title>!p
	1,.d
}
f MAIN
B LOCAL
b MAIN
/Local Forecast/,$m "LOCAL"
b MAIN
,x/<[aA] ([^>]|\n)+>/ .,/<\/[aA]>/d
,x/<([^>]|\n)+>/d
,x/>/d
,x/Yahoo!.+\n/d
/^F°.+\n/d
/^&#139;10/;/^100\+\n/d
0;0/^ *-.+\n/d
0/.*[0-9]+°/,$-/^(Sunset|Barometer).+\n/m0/^Today\n/
/^Today/,$-/(^Sunset|Barometer)/ x/\n\n+/c/\n/
/^Today/;.+3 s/\n/ /g
/^Current conditions/,/^Neighboring.+\n/d
,x/\n *(\n *)+/c/\n\n/
,x/^(Sun|Mon|Tue|Wed|Thu|Fri|Sat)$/ a/:/
0/^(Haze|Snow|Windy|Rain|Showers|Sunny|((Most|Part)ly *)?Cloudy)/m0/:$/
0/^(Haze|Snow|Windy|Rain|Showers|Sunny|((Most|Part)ly *)?Cloudy)/m0/:$/
0/^(Haze|Snow|Windy|Rain|Showers|Sunny|((Most|Part)ly *)?Cloudy)/m0/:$/
0/^(Haze|Snow|Windy|Rain|Showers|Sunny|((Most|Part)ly *)?Cloudy)/m0/:$/
,x/^(Sun|Mon|Tue|Wed|Thu|Fri|Sat):.*/ a/:/
0/^Hi .*/m0/:$/
0/^Hi .*/m0/:$/
0/^Hi .*/m0/:$/
0/^Hi .*/m0/:$/
,x/^(Sun|Mon|Tue|Wed|Thu|Fri|Sat):.*/ a/:/
0/^Lo .*/m0/:$/
0/^Lo .*/m0/:$/
0/^Lo .*/m0/:$/
0/^Lo .*/m0/:$/
/^Copyright.+\n/d
,x/ *-/d
,x/&gt;/d
,x/ *=/d
,x/\n *(\n *)+/c/\n\n/
0/\n+/d
,p
b LOCAL
,x/<[aA] [^>]+>/ .,/<\/[aA]>/d
,x/<([^>]|\n)+>/d
/^Copyright.+\n/d
,x/ *-/d
,x/ *=/d
,x/\n *(\n *)+/c/\n\n/
,p
!