Split things up a bit.

Also start approximating the look and feel

Entry.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <string>
+#include <filesystem>
+
+struct Entry
+{
+	std::string name;
+	std::string perms;
+	bool is_dir;
+	bool is_exe;
+};
+
+bool is_exe( std::filesystem::directory_entry entry );
+
+std::string drwx( std::filesystem::directory_entry entry );
+
+std::string format_entry( const Entry &entry, std::size_t widest );

Makefile

@@ -5,7 +5,12 @@ CPPFLAGS+= -I.
 
 LDFLAGS+= -Wl,-rpath,'$$ORIGIN/'
 
+OBJECTS= helpers.o format.o cudir.o
+
 all: cudir
 
+cudir: $(OBJECTS)
+	$(CXX) -o $@ $(OBJECTS)
+
 clean:
-	rm -f cudir
+	rm -f cudir *.o

cudir.cc

@@ -3,72 +3,11 @@
 #include <algorithm>
 #include <filesystem>
 
-bool
+#include "Entry.h"
-is_exe( const std::filesystem::directory_entry entry )
+
+auto
+getEntries( const std::filesystem::path where )
 {
-	using std::filesystem::perms;
-	auto p= status( entry.path() ).permissions();
-
-	return ( perms::none != ( p & ( perms::owner_exec | perms::group_exec | perms::others_exec ) ) );
-}
-
-std::string
-drwx( const std::filesystem::directory_entry entry )
-{
-	auto p= status( entry.path() ).permissions();
-
-	std::ostringstream oss;
-	using std::filesystem::perms;
-	auto show = [&](const char op, const perms perm)
-	{
-		oss << (perms::none == (perm bitand p) ? '-' : op);
-	};
-	oss << ( entry.is_directory() ? 'd' : '-' );
-	show('r', perms::owner_read);
-	show('w', perms::owner_write);
-	show('x', perms::owner_exec);
-	show('r', perms::group_read);
-	show('w', perms::group_write);
-	show('x', perms::group_exec);
-	show('r', perms::others_read);
-	show('w', perms::others_write);
-	show('x', perms::others_exec);
-
-	return std::move( oss ).str();
-}
-
-struct Entry
-{
-	std::string name;
-	std::string perms;
-	bool is_dir;
-	bool is_exe;
-};
-
-std::string
-format_entry( const Entry &entry, const std::size_t widest )
-{
-	std::ostringstream oss;
-	oss << "[";
-
-	if( entry.is_dir )
-	{
-		oss << "1;35;95";
-	}
-	else if( entry.is_exe )
-	{
-		oss << "1;36;96";
-	}
-	oss << 'm' << std::setw( widest + 8 ) << std::left << entry.name;
-
-	return std::move( oss ).str();
-}
-
-int
-main()
-{
-	std::filesystem::path where="./";
-
 	std::vector< Entry > entries;
 
 	for( const auto &entry: std::filesystem::directory_iterator{ where } )
@@ -76,9 +15,30 @@ main()
 		entries.emplace_back( entry.path().filename(), drwx( entry ), entry.is_directory(), is_exe( entry ) );
 	}
 
+	std::sort( begin( entries ), end( entries ), []( const auto &lhs, const auto &rhs ) { return lhs.name < rhs.name; } );
+
+	return entries;
+}
+
+int
+main()
+{
+	std::filesystem::path where="./";
+
+	const auto entries= getEntries( where );
+
 	const auto widest= std::max_element( begin( entries ), end( entries ),
 			[]( const auto &lhs, const auto &rhs ) { return lhs.name.size() < rhs.name.size(); } )->name.size();
 
+	const int rowWidth= widest + 8 + 5 + 3 + 10 + 2;
+
+	std::cout << "";
+	for( int i= 0; i < rowWidth; ++i ) std::cout << "\u2500";
+	std::cout << "\u252c";
+	for( int i= 0; i < rowWidth; ++i ) std::cout << "\u2500";
+	std::cout << "" << std::endl;
+
+	bool side= false;
 	for( const auto &entry: entries )
 	{
 		std::cout << format_entry( entry, widest ) << " ";
@@ -92,8 +52,25 @@ main()
 		}
 		std::cout << "  ";
 		std::cout << "" << entry.perms << "";
-		std::cout << "  |" << std::endl;
+		std::cout << "  ";
+		if( side == false )
+		{
+			std::cout << "\u2502";
+			side= true;
+		}
+		else
+		{
+			side= false;
+			std::cout << std::endl;
+		}
 	}
+	if( side ) std::cout << std::endl;
+
+	std::cout << "";
+	for( int i= 0; i < rowWidth; ++i ) std::cout << "\u2500";
+	std::cout << "\u2534";
+	for( int i= 0; i < rowWidth; ++i ) std::cout << "\u2500";
+	std::cout << "" << std::endl;
 
 	return EXIT_SUCCESS;
 }

format.cc

@@ -0,0 +1,24 @@
+#include "Entry.h"
+
+#include <sstream>
+#include <iostream>
+
+std::string
+format_entry( const Entry &entry, const std::size_t widest )
+{
+	std::ostringstream oss;
+	oss << "[";
+
+	if( entry.is_dir )
+	{
+		oss << "1;35;95";
+	}
+	else if( entry.is_exe )
+	{
+		oss << "1;36;96";
+	}
+	oss << 'm' << std::setw( widest + 8 ) << std::left << entry.name;
+
+	return std::move( oss ).str();
+}
+

helpers.cc

@@ -0,0 +1,39 @@
+#include "Entry.h"
+
+#include <sstream>
+#include <algorithm>
+#include <filesystem>
+
+bool
+is_exe( const std::filesystem::directory_entry entry )
+{
+	using std::filesystem::perms;
+	auto p= status( entry.path() ).permissions();
+
+	return ( perms::none != ( p & ( perms::owner_exec | perms::group_exec | perms::others_exec ) ) );
+}
+
+std::string
+drwx( const std::filesystem::directory_entry entry )
+{
+	auto p= status( entry.path() ).permissions();
+
+	std::ostringstream oss;
+	using std::filesystem::perms;
+	auto show = [&](const char op, const perms perm)
+	{
+		oss << (perms::none == (perm bitand p) ? '-' : op);
+	};
+	oss << ( entry.is_directory() ? 'd' : '-' );
+	show('r', perms::owner_read);
+	show('w', perms::owner_write);
+	show('x', perms::owner_exec);
+	show('r', perms::group_read);
+	show('w', perms::group_write);
+	show('x', perms::group_exec);
+	show('r', perms::others_read);
+	show('w', perms::others_write);
+	show('x', perms::others_exec);
+
+	return std::move( oss ).str();
+}