hooks/post-install: add hook to rewrite unversioned python shebangs.

common/hooks/post-install/07-rewrite-python-shebang.sh

@@ -0,0 +1,27 @@
+# This hook executes the following tasks:
+#	- rewrites python shebangs with the corresponding python version
+
+hook() {
+	local pyver= shebang= warn=
+
+	for i in $python_versions; do
+		if [ "$pyver" ]; then
+			warn=1
+			break;
+		fi
+		pyver=$i
+	done
+
+	: ${pyver:=2.7}
+	shebang="#!/usr/bin/python$pyver"
+	find ${PKGDESTDIR} -type f -print0 | \
+		xargs -0 grep -l -m 1 "^#!.*\([[:space:]]\|/\)python\([[:space:]]\|$\)" -- | while read f; do
+		if [ "$warn" ]; then
+			msg_warn "$pkgname: multiple python versions defined!"
+			msg_warn "$pkgname: using $pyver for shebang"
+			warn=
+		fi
+		echo "   Unversioned shebang replaced by '$shebang': ${f#$PKGDESTDIR}"
+		sed -i "1s@.*python@${shebang}@" -- "$f"
+	done
+}