clear env by default

src/main.rs

@@ -156,7 +156,7 @@ examples
     if opts.exec.len() > 1 {
         cmd.args(&opts.exec[1..]);
     }
-    if opts.clear_env {
+    if !opts.retain_env {
         for (k, _) in std::env::vars() {
             unsafe {
                 std::env::remove_var(k);

src/parse.rs

@@ -138,11 +138,11 @@ pub fn parse_args() -> Result<Yoke> {
                 cur_arg = Unset;
                 yoke.signals = true;
             }
-            "--clear-env" | "-c" => {
+            "--retain-env" | "-r" => {
                 collect_args(&mut yoke, &collector, &cur_arg)?;
                 collector.clear();
                 cur_arg = Unset;
-                yoke.clear_env = true;
+                yoke.retain_env = true;
             }
             "--ldd" | "-l" => {
                 collect_args(&mut yoke, &collector, &cur_arg)?;

src/types.rs

@@ -5,7 +5,7 @@ pub struct Yoke {
     pub fs: HashMap<Permissions, Vec<PathBuf>>,
     pub tcp: HashMap<Direction, Vec<u16>>,
     pub env: HashMap<String, String>,
-    pub clear_env: bool,
+    pub retain_env: bool,
     pub signals: bool,
     pub sockets: bool,
     pub ldd: bool,