permissions after a pull

diff --git a/permissions.sh b/permissions.sh
new file mode 100755 (executable)
index 0000000..d8b2bd5
--- /dev/null
+++ b/permissions.sh
@@ -0,0 +1,26 @@
+#!/bin/bash
+# permissions.sh
+# do this after a git clone
+# Make incommon/{executable,library} group-readable and non-group-writable,
+# preserving existing execute bits (via X).
+
+set -euo pipefail
+
+BASE=${1:-incommon}
+
+if [ ! -d "$BASE" ]; then
+  echo "Error: $BASE is not a directory" >&2
+  exit 1
+fi
+
+# 1. Let group members enter the top-level incommon directory
+chmod g+rx "$BASE"
+
+# 2. Fix permissions on executable/ and library/ subtrees
+for sub in executable library; do
+  if [ -d "$BASE/$sub" ]; then
+    chmod -R g+rX,g-w "$BASE/$sub"
+  else
+    echo "Note: $BASE/$sub does not exist, skipping" >&2
+  fi
+done