docs: add requirements

...duh

README.md

@@ -4,12 +4,17 @@
 
 a simple shift register built on piperw(1)
 
+requirements:
+- execline (obviously)
+- s6-portable-utils (s6-expr, s6-ls, s6-tail)
+
 ### usage
 
 ```
 init-state <name>
 load-state <name> <target>
 save-state <name> <value>
+nuke-state <name>
 ```
 
 ```sh
@@ -17,15 +22,18 @@ save-state <name> <value>
 
 init-state flip
 save-state flip "up"
-forstdin -E line
-	load-state flip current
-	println "! state: $current"
-	ifelse { s6-test "$line" = "flip" } {
-		println "! flipping state"
-		ifelse { s6-test "$current" = "up" } {
-			save-state flip "down"
+foreground {
+	forstdin -E line
+		load-state flip current
+		println "! state: $current"
+		ifelse { s6-test "$line" = "flip" } {
+			println "! flipping state"
+			ifelse { s6-test "$current" = "up" } {
+				save-state flip "down"
+			}
+			save-state flip "up"
 		}
-		save-state flip "up"
-	}
-	save-state flip "$current"
+		save-state flip "$current"
+}
+nuke-state flip
 ```

nuke-state

@@ -0,0 +1,12 @@
+#!/bin/execlineb
+
+importas -ui name 1
+importas -ui rdfd ELSTATE_${name}
+backtick -E wrfd { s6-expr "$rdfd" + 1 }
+
+fdclose ${rdfd}
+fdclose ${wrfd}
+
+shift
+elgetpositionals
+$@