add toggles

Author: kpedro88

README.md

@@ -104,14 +104,23 @@ or placed in a file `~/.callhostrc` (automatically detected and sourced by `call
     ```bash
     export CALL_HOST_STATUS=${CALL_HOST_STATUS:=disable}
     ```
-    Then to enable it temporarily:
+    Use the dedicated toggle to enable it for the rest of your session (or until another toggle is called):
+    ```bash
+    call_host_enable
+    ```
+    or just enable it for one container invocation:
     ```bash
     CALL_HOST_STATUS=enable cmssw-el7 ...
     ```
-* Instead, if you have this enabled by default and you want to temporarily disable this for a specific container invocation:
+* Instead, if you have this enabled by default and want to disable it on the fly:  
+    Use the dedicated toggle to disable it for the rest of your session (or until another toggle is called):
+    ```bash
+    call_host_disable
+    ```
+    or just disable it for one container invocation:
     ```bash
     CALL_HOST_STATUS=disable cmssw-el7 ...
-    ````
+    ```
 
 ### Caveats
 

call_host.sh

@@ -40,6 +40,16 @@ fi
 # ensure the pipe dir is bound
 export APPTAINER_BIND=${APPTAINER_BIND}${APPTAINER_BIND:+,}${CALL_HOST_DIR}
 
+# enable/disable toggles
+call_host_enable(){
+	export CALL_HOST_STATUS=enable
+}
+export -f call_host_enable
+call_host_disable(){
+	export CALL_HOST_STATUS=disable
+}
+export -f call_host_disable
+
 # concept based on https://stackoverflow.com/questions/32163955/how-to-run-shell-script-on-host-from-docker-container
 
 # execute command sent to host pipe; send output to container pipe; store exit code