add: friendly path-export & open startfiles for bash

bash/bash-open-startfiles.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+# lists all files, an interactive login-shell with bash would try to open. Useful to find the correct order of .bashrc .profile and such.
+
+echo exit | strace bash -li |& grep '^open'

bash/friendly_path-export.sh

@@ -0,0 +1,6 @@
+#/!bin/bash
+
+# exports a path only, if $PATH does not already contains the path.
+
+NEWPATH="$1"
+echo ":$PATH:" | grep -q ":$NEWPATH:" || export PATH="$PATH:$NEWPATH"