Shell: Use Core::Environment instead of manually iterating environ

Userland/Shell/Builtin.cpp

@@ -13,6 +13,7 @@
 #include <AK/ScopeGuard.h>
 #include <AK/Statistics.h>
 #include <LibCore/ArgsParser.h>
+#include <LibCore/Environment.h>
 #include <LibCore/EventLoop.h>
 #include <LibCore/File.h>
 #include <LibCore/System.h>
@@ -636,8 +637,8 @@ ErrorOr<int> Shell::builtin_export(Main::Arguments arguments)
         return 1;
 
     if (vars.is_empty()) {
-        for (size_t i = 0; environ[i]; ++i)
-            puts(environ[i]);
+        for (auto entry : Core::Environment::entries())
+            outln("{}", entry.full_entry);
         return 0;
     }
 

Userland/Shell/Shell.cpp

@@ -23,6 +23,7 @@
 #include <AK/URL.h>
 #include <LibCore/DateTime.h>
 #include <LibCore/DirIterator.h>
+#include <LibCore/Environment.h>
 #include <LibCore/Event.h>
 #include <LibCore/EventLoop.h>
 #include <LibCore/File.h>
@@ -1726,13 +1727,11 @@ Vector<Line::CompletionSuggestion> Shell::complete_variable(StringView name, siz
     }
 
     // Look at the environment.
-    for (auto i = 0; environ[i]; ++i) {
-        StringView entry { environ[i], strlen(environ[i]) };
-        if (entry.starts_with(pattern)) {
-            auto parts = entry.split_view('=');
-            if (parts.is_empty() || parts.first().is_empty())
+    for (auto entry : Core::Environment::entries()) {
+        if (entry.full_entry.starts_with(pattern)) {
+            if (entry.name.is_empty())
                 continue;
-            ByteString name = parts.first();
+            auto name = entry.name.to_byte_string();
             if (suggestions.contains_slow(name))
                 continue;
             suggestions.append(move(name));