Zpkgs tv genid: init

1 files changed, 21 insertions, 0 deletions

diff --git a/Zpkgs/tv/genid.nix b/Zpkgs/tv/genid.nix
new file mode 100644
index 000000000..22ef6d29b
--- /dev/null
+++ b/Zpkgs/tv/genid.nix
@@ -0,0 +1,21 @@
+{ lib, pkgs, ... }:
+
+pkgs.writeScriptBin "genid" ''
+  #! /bin/sh
+  # usage: genid NAME
+  set -euf
+
+  export PATH=${lib.makeSearchPath "bin" (with pkgs; [
+    bc
+    coreutils
+  ])}
+
+  name=$1
+  hash=$(printf %s "$name" | sha1sum | cut -d\  -f1 | tr a-f A-F)
+  echo "
+    min=2^16  # bigger than nobody and nogroup, see <nixos/modules/misc/ids.nix>
+    max=2^32  # see 2^(8*sizeof(uid_t))
+    ibase=16
+    ($hash + min) % max
+  " | bc
+''