ref: 4a8bc7aa008f753c082a914a0f95ea3df09d2123
dir: /lib/std/env+plan9.myr/
use sys
use "alloc"
use "blat"
use "cstrconv"
use "die"
use "extremum"
use "fmt"
use "option"
use "result"
use "slcp"
use "sldup"
use "sleq"
use "slpush"
use "slurp"
use "threadhooks"
use "traits"
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.eq(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)
}