extfs: tester: export some more useful variables.

New environment variables:

- MC_TEST_EXTFS_DATA_DIR
- MC_TEST_EXTFS_INPUT

Signed-off-by: Mooffie <mooffie@gmail.com>

tests/src/vfs/extfs/helpers-list/README

@@ -142,8 +142,12 @@ This is the tester itself. You invoke it with `make check`, or with the
 `run` script. Invoking it directly is a bit involving because you need to
 provide it with 2 or 3 directory paths. `run` does this work for you.
 
-MC_TEST_EXTFS_LIST_CMD
-----------------------
+Environment variables
+---------------------
+
+### Frequently used variables ###
+
+#### MC_TEST_EXTFS_LIST_CMD ####
 
 When a helper runs under the tester, the environment variable
 `MC_TEST_EXTFS_LIST_CMD` holds the command that's to provide input. The
@@ -169,3 +173,15 @@ To make this helper testable, we need to change the first line to:
 The command in `MC_TEST_EXTFS_LIST_CMD` is a black-box for the helper,
 and it intentionally ignores any arguments passed to it (so that `lq
 "$ARCHIVE"`, above, won't cause problems).
+
+### Infrequently used variables ###
+
+#### MC_TEST_EXTFS_INPUT ####
+
+Contains the path of the [input file]. You'll more commonly use
+[MC_TEST_EXTFS_LIST_CMD], though.
+
+#### MC_TEST_EXTFS_DATA_DIR ####
+
+Contains the path of [the data folder]. Use it when you need to
+construct the paths of other files you store there.

tests/src/vfs/extfs/helpers-list/test_all

@@ -177,6 +177,25 @@ find_helper() {
   fi
 }
 
+#
+# Export variables to be used by tests.
+#
+# See README for their documentation.
+#
+export_useful_variables() {
+  local input="$1"
+
+  # Frequently used variables:
+  MC_TEST_EXTFS_LIST_CMD="mc_xcat $input"  # reason #2 we don't allow spaces in pathnames.
+  export MC_TEST_EXTFS_LIST_CMD
+
+  # Infrequently used variables:
+  MC_TEST_EXTFS_INPUT=$input
+  export MC_TEST_EXTFS_INPUT
+  MC_TEST_EXTFS_DATA_DIR=$data_dir
+  export MC_TEST_EXTFS_DATA_DIR
+}
+
 #
 # The crux of this program.
 #
@@ -235,8 +254,7 @@ run() {
     #
 
     (
-    MC_TEST_EXTFS_LIST_CMD="mc_xcat $input"  # reason #2 we don't allow spaces in pathnames.
-    export MC_TEST_EXTFS_LIST_CMD
+    export_useful_variables "$input"
     if [ -f "$env_vars_file" ]; then
       set -a  # "allexport: Export all variables assigned to."
       . "$env_vars_file"