1 files changed, 57 insertions, 0 deletions
diff --git a/ves-unset.sh b/ves-unset.sh
new file mode 100644
index 0000000..d25a178
--- /dev/null
+++ b/ves-unset.sh
@@ -0,0 +1,57 @@
+#!/bin/sh
+#
+# Remove a variable from an sh-ves environment entirely; the inverse of
+# ves export. If the target environment is currently active, the live
+# variable is restored to its pre-activation value, just as ves deactivate
+# would do.
+#
+ves_unset() {
+    env=""
+    case $1 in
+        --env=*)
+            env="${1#--env=}"
+            shift
+            ;;
+    esac
+
+    if [ "$#" -lt 1 ]; then
+        printf "ERROR: No variable specified. usage: ves unset [--env=<name>] <variable>\n" >&2
+        return 2
+    fi
+
+    var="$1"
+
+    if ! env=$(_shves_resolve_env "$env"); then
+        return 1
+    fi
+
+    if ! _shves_check_var_name "$var"; then
+        return 1
+    fi
+
+    fname="$SHVES_ENV_DIR/$env"
+    if ! _shves_has_var "$fname" "$var"; then
+        printf "ERROR: Variable [%s] does not exist in environment [%s].\n" "$var" "$env" >&2
+        return 1
+    fi
+
+    _shves_del_var "$fname" "$var"
+
+    # If the target environment is active and the variable was part of the
+    # activation save-state, restore the pre-activation value in the live
+    # shell and drop the variable from the bookkeeping.
+    if [ "$env" = "$SHVES_ENV_NM" ] && _shves_is_saved "$var"; then
+        _shves_restore_var "$var"
+
+        new_saved=""
+        for v in $SHVES_SAVED_VARS; do
+            if [ "$v" != "$var" ]; then
+                new_saved="$new_saved $v"
+            fi
+        done
+        SHVES_SAVED_VARS="$new_saved"
+        export SHVES_SAVED_VARS
+    fi
+
+    return 0
+}