Implement in shell scripts

fish/default.nix

@@ -0,0 +1,22 @@
+{ stdenv
+, lib
+, fish
+, makeWrapper
+}:
+
+stdenv.mkDerivation {
+  pname = "soe-fish";
+  version = "1.0";
+
+  src = ./.;
+
+  buildInputs = [ fish ];
+  nativeBuildInputs = [ makeWrapper ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    install -m555 soe-fish $out/bin
+    wrapProgram $out/bin/soe-fish \
+      --prefix PATH : ${lib.makeBinPath [ fish ]}
+  '';
+}

fish/soe-fish

@@ -0,0 +1,17 @@
+#!/usr/bin/env fish
+
+read -P "" num
+echo
+
+set nums (seq 2 $num)
+
+while test -n "$nums"
+    set prime $nums[1]
+    echo $prime
+
+    set -e nums_
+    for elem in $nums
+        test (math $elem % $prime) -eq 0 || set -a nums_ $elem
+    end
+    set nums $nums_
+end