ref: b4252aeded2d15592fe940e20f533f113000c61d
dir: /lib/std/env+plan9.myr/
use sys
use "alloc"
use "cstrconv"
use "die"
use "extremum"
use "fmt"
use "option"
use "result"
use "slcp"
use "sldup"
use "sleq"
use "slpush"
use "slurp"
use "blat"
use "threadhooks"
pkg std =
	const getenv	: (name : byte[:] -> option(byte[:]))
	const getenvv	: (name : byte[:], default : byte[:] -> byte[:])
	const setenv	: (name : byte[:], val : byte[:] -> void)
;;
var envkey 	: byte[:][:]
var envval	: byte[:][:]
const envfind = {key
	lock(envlck)
	for var i = 0; i < envkey.len; i++
		if std.sleq(envkey[i], key)
			unlock(envlck)
			-> `Some envval[i]
		;;
	;;
	unlock(envlck)
	-> `None
}
const getenv = {name
	var s, ret
	match envfind(name)
	| `Some val:
		ret = `Some val
	| `None:
		s = fmt("/env/{}", name)
		match std.slurp(s)
		| `Err m: 
			ret = `None
		| `Ok data:
			data = cstrconv(data)
			lock(envlck)
			slpush(&envkey, sldup(data))
			slpush(&envval, data)
			unlock(envlck)
			ret = `Some data
		;;
		std.slfree(s)
	;;
	-> ret
}
const getenvv = {name, default
	match getenv(name)
	| `Some val:	-> val
	| `None:	-> default
	;;
}
const setenv = {name, val
	var p
	p = fmt("/env/{}", name)
	blat(p, val, 0o644)
	slfree(p)
}