Merge remote-tracking branch 'cd/master'

1 files changed, 22 insertions, 0 deletions

diff --git a/krebs/4lib/shell.nix b/krebs/4lib/shell.nix
new file mode 100644
index 000000000..2a6da5c16
--- /dev/null
+++ b/krebs/4lib/shell.nix
@@ -0,0 +1,22 @@
+{ lib, ... }:
+
+with builtins;
+with lib;
+
+rec {
+  escape =
+    let
+      isSafeChar = c: match "[-./0-9_a-zA-Z]" c != null;
+    in
+    stringAsChars (c:
+      if isSafeChar c then c
+      else if c == "\n" then "'\n'"
+      else "\\${c}");
+
+  #
+  # shell script generators
+  #
+
+  # example: "${cat (toJSON { foo = "bar"; })} | jq -r .foo"
+  cat = s: "printf '%s' ${escape s}";
+}