diff --git a/include/processing.hpp b/include/processing.hpp
index 5f1941f..dfa6158 100644
--- a/include/processing.hpp
+++ b/include/processing.hpp
@@ -70,6 +70,7 @@ void list_fcts(_obj* in, std::regex const& exclude);
 void list_cmds(_obj* in, std::regex const& exclude);
 
 // recursives
+bool r_has_env_set(_obj* in, bool* result);
 bool r_get_unsets(_obj* in, set_t* unsets);
 bool r_get_var(_obj* in, countmap_t* defmap, countmap_t* callmap);
 bool r_get_cmd(_obj* in, countmap_t* all_cmds);
@@ -81,6 +82,7 @@ bool r_delete_var(_obj* in, set_t* vars);
 
 std::set<std::string> find_lxsh_commands(shmain* sh);
 void add_unset_variables(shmain* sh, std::regex const& exclude);
+bool has_env_set(_obj* in);
 
 void string_processors(_obj* in);
 
diff --git a/include/struc.hpp b/include/struc.hpp
index 0f8e258..3f6ae6c 100644
--- a/include/struc.hpp
+++ b/include/struc.hpp
@@ -400,6 +400,9 @@ public:
   bool is_argvar();
   std::vector<subarg*> subarg_vars();
 
+  // returns true if command performs env var changes
+  bool has_var_assign();
+
   arglist* args;
 
   std::string generate(int ind, generate_context* ctx);
diff --git a/src/main.cpp b/src/main.cpp
index decb51f..739ff17 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -180,12 +180,6 @@ int main(int argc, char* argv[])
       list_fcts(sh, re_fct_exclude);
     else if(options["list-cmd"])
       list_cmds(sh, regex_null);
-#ifdef DEBUG_MODE
-    else if(options['J'])
-    {
-      std::cout << gen_json_struc(sh) << std::endl;
-    }
-#endif
     // output
     else
     {
@@ -217,6 +211,14 @@ int main(int argc, char* argv[])
       if(options["unset-var"])
         add_unset_variables( sh, re_var_exclude );
 
+  #ifdef DEBUG_MODE
+      if(options['J'])
+      {
+        std::cout << gen_json_struc(sh) << std::endl;
+        goto end;
+      }
+  #endif
+
       if(options['o']) // file output
       {
         std::string destfile=options['o'];
@@ -257,6 +259,7 @@ int main(int argc, char* argv[])
     std::cerr << e.what() << std::endl;
     return ERR_RUNTIME;
   }
+end:
 
   delete sh;
 
diff --git a/src/minify.cpp b/src/minify.cpp
index a639cb8..4a97000 100644
--- a/src/minify.cpp
+++ b/src/minify.cpp
@@ -436,7 +436,65 @@ bool r_minify_empty_manip(_obj* in)
   return true;
 }
 
+block* do_one_minify_single_block(block* in)
+{
+  block* ret=nullptr;
+  list* l=nullptr;
+  if(in->type == _obj::block_brace)
+    l = dynamic_cast<brace*>(in)->lst;
+  else if(in->type == _obj::block_subshell)
+    l = dynamic_cast<subshell*>(in)->lst;
+
+  if(l == nullptr)
+    return nullptr;
+
+  // not a single cmd/block: not applicable
+  if(l->cls.size() != 1 || l->cls[0]->pls.size() != 1 || l->cls[0]->pls[0]->cmds.size() != 1)
+    return nullptr;
+
+  ret = l->cls[0]->pls[0]->cmds[0];
+
+  // if is a subshell and has some env set: don't remove it
+  if(in->type == _obj::block_subshell && has_env_set(in))
+    return nullptr;
+
+  return ret;
+}
+
+bool r_minify_single_block(_obj* in)
+{
+  switch(in->type)
+  {
+    case _obj::_pipeline: {
+      pipeline* t = dynamic_cast<pipeline*>(in);
+      for(uint32_t i=0; i<t->cmds.size(); i++)
+      {
+        block* ret = do_one_minify_single_block(t->cmds[i]);
+        if(ret != nullptr) {
+          // concatenate redirects
+          for(uint32_t i=0; i<t->cmds[i]->redirs.size(); i++)
+            ret->redirs.insert(ret->redirs.begin()+i, ret->redirs[i]);
+
+          // deindex
+          t->cmds[i]->redirs.resize(0);
+          if(t->cmds[i]->type == _obj::block_brace)
+            dynamic_cast<brace*>(t->cmds[i])->lst->cls[0]->pls[0] = nullptr;
+          else if(t->cmds[i]->type == _obj::block_subshell)
+            dynamic_cast<subshell*>(t->cmds[i])->lst->cls[0]->pls[0] = nullptr;
+
+          // replace value
+          delete t->cmds[i];
+          t->cmds[i] = ret;
+        }
+      }
+    }; break;
+    default: break;
+  }
+  return true;
+}
+
 void minify_generic(_obj* in)
 {
   recurse(r_minify_empty_manip, in);
+  recurse(r_minify_single_block, in);
 }
diff --git a/src/processing.cpp b/src/processing.cpp
index df30b57..6b95d29 100644
--- a/src/processing.cpp
+++ b/src/processing.cpp
@@ -265,8 +265,33 @@ void add_unset_variables(shmain* sh, std::regex const& exclude)
   }
 }
 
+bool has_env_set(_obj* in) {
+  bool r=false;
+  recurse(r_has_env_set, in, &r);
+  return r;
+}
+
 /** RECURSIVES **/
 
+// CHECK //
+
+bool r_has_env_set(_obj* in, bool* result)
+{
+  switch(in->type)
+  {
+    case _obj::block_subshell: {
+      return false;
+    }; break;
+    case _obj::block_cmd: {
+      cmd* t = dynamic_cast<cmd*>(in);
+      if(t->has_var_assign())
+        *result = true;
+    }
+    default: break;
+  }
+  return true;
+}
+
 // GET //
 
 bool r_get_var(_obj* in, countmap_t* defmap, countmap_t* callmap)
diff --git a/src/struc_helper.cpp b/src/struc_helper.cpp
index 85235c1..1f44bff 100644
--- a/src/struc_helper.cpp
+++ b/src/struc_helper.cpp
@@ -138,6 +138,15 @@ bool possibly_expands(arglist* in)
 
 // property getters
 
+bool cmd::has_var_assign()
+{
+  if(this->args->size() == 0)
+  {
+    return this->var_assigns.size()>0;
+  }
+  return this->is_argvar();
+}
+
 size_t cmd::arglist_size()
 {
   if(args==nullptr)