improve ensureZfsMounted script

overlays.nix

@@ -3,31 +3,31 @@ final: prev: {
     name = "zfsEnsureMounted";
     runtimeInputs = with prev; [
       zfs
-      gnugrep
       gawk
       coreutils
     ];
 
     text = ''
-      #!/bin/sh -x
+       #!/bin/sh
 
-      if [[ "$#" -eq "0" ]]; then
-         echo "no arguments passed"
-         exit 1
-      fi
+       if [[ "$#" -eq "0" ]]; then
+          echo "no arguments passed"
+          exit 1
+       fi
 
-      TARGETS=$(echo "$@" | sort | uniq)
-      MOUNTED=$(zfs list -o mountpoint,mounted -H | awk '$2 == "yes" {print $1}' | sort | uniq)
-      NUM_MATCHED=$(echo "$MOUNTED" | grep -Ec "$(echo "$@" | tr ' ' '\|')") # does not properly handle paths with strings
-      if [[ "$NUM_MATCHED" -eq "$#" ]]; then
-         exit 0
-      fi
+      MOUNTED=$(zfs list -o mountpoint,mounted -H | awk '$NF == "yes" {$NF=""; print $0}' | sed 's/[[:space:]]*$//')
 
-      FOUND=$(printf "%s\n%s" "$TARGETS" "$MOUNTED" | sort | uniq -c | awk '$1 == "2" {print $2}' | sort)
-      MISSING=$(printf "%s\n%s" "$FOUND" "$TARGETS" | sort | uniq -u | sort)
+       MISSING=""
+       for target in "$@"; do
+          if ! echo "$MOUNTED" | grep -Fxq "$target"; then
+             MISSING="$MISSING $target"
+          fi
+       done
 
-      echo "FAILURE, missing: $MISSING" 1>&2
-      exit 1
+       if [[ -n "$MISSING" ]]; then
+          echo "FAILURE, missing:$MISSING" 1>&2
+          exit 1
+       fi
     '';
   };
 }