LibCore+Everywhere: Return an Error from DirIterator::error()

This also removes DirIterator::error_string(), since the same strerror()
string will be included when you print the Error itself. Except in `ls`
which is still using fprintf() for now.

Userland/Utilities/du.cpp

@@ -142,8 +142,9 @@ ErrorOr<u64> print_space_usage(DeprecatedString const& path, DuOption const& du_
     if (is_directory) {
         auto di = Core::DirIterator(path, Core::DirIterator::SkipParentAndBaseDir);
         if (di.has_error()) {
-            outln("du: cannot read directory '{}': {}", path, di.error_string());
-            return Error::from_string_literal("An error occurred. See previous error.");
+            auto error = di.error();
+            outln("du: cannot read directory '{}': {}", path, error);
+            return error;
         }
 
         while (di.has_next()) {

Userland/Utilities/ls.cpp

@@ -170,7 +170,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
             if (di.has_error()) {
                 status = 1;
-                fprintf(stderr, "%s: %s\n", path.characters(), di.error_string());
+                fprintf(stderr, "%s: %s\n", path.characters(), strerror(di.error().code()));
             }
 
             while (di.has_next()) {
@@ -396,7 +396,8 @@ static int do_file_system_object_long(char const* path)
     Core::DirIterator di(path, flags);
 
     if (di.has_error()) {
-        if (di.error() == ENOTDIR) {
+        auto error = di.error();
+        if (error.code() == ENOTDIR) {
             struct stat stat {
             };
             int rc = lstat(path, &stat);
@@ -406,7 +407,7 @@ static int do_file_system_object_long(char const* path)
                 return 0;
             return 2;
         }
-        fprintf(stderr, "%s: %s\n", path, di.error_string());
+        fprintf(stderr, "%s: %s\n", path, strerror(di.error().code()));
         return 1;
     }
 
@@ -510,7 +511,8 @@ int do_file_system_object_short(char const* path)
 
     Core::DirIterator di(path, flags);
     if (di.has_error()) {
-        if (di.error() == ENOTDIR) {
+        auto error = di.error();
+        if (error.code() == ENOTDIR) {
             size_t nprinted = 0;
             bool status = print_filesystem_object_short(path, path, &nprinted);
             printf("\n");
@@ -518,7 +520,7 @@ int do_file_system_object_short(char const* path)
                 return 0;
             return 2;
         }
-        fprintf(stderr, "%s: %s\n", path, di.error_string());
+        fprintf(stderr, "%s: %s\n", path, strerror(di.error().code()));
         return 1;
     }
 

Userland/Utilities/lsblk.cpp

@@ -27,8 +27,9 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
     Core::DirIterator di("/sys/devices/storage/", Core::DirIterator::SkipParentAndBaseDir);
     if (di.has_error()) {
-        warnln("Failed to open /sys/devices/storage - {}", di.error());
-        return 1;
+        auto error = di.error();
+        warnln("Failed to open /sys/devices/storage - {}", error);
+        return error;
     }
 
     outln(format_row, "LUN"sv, "Command set"sv, "Block Size"sv, "Last LBA"sv);

Userland/Utilities/lspci.cpp

@@ -70,8 +70,9 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
     Core::DirIterator di("/sys/bus/pci/", Core::DirIterator::SkipParentAndBaseDir);
     if (di.has_error()) {
-        warnln("Failed to open /sys/bus/pci - {}", di.error());
-        return 1;
+        auto error = di.error();
+        warnln("Failed to open /sys/bus/pci - {}", error);
+        return error;
     }
 
     TRY(Core::System::pledge("stdio rpath"));

Userland/Utilities/mount.cpp

@@ -129,8 +129,8 @@ static ErrorOr<void> mount_all()
 
     auto fstab_directory_iterator = Core::DirIterator("/etc/fstab.d", Core::DirIterator::SkipDots);
 
-    if (fstab_directory_iterator.has_error() && fstab_directory_iterator.error() != ENOENT) {
-        dbgln("Failed to open /etc/fstab.d: {}", fstab_directory_iterator.error_string());
+    if (fstab_directory_iterator.has_error() && fstab_directory_iterator.error().code() != ENOENT) {
+        dbgln("Failed to open /etc/fstab.d: {}", fstab_directory_iterator.error());
     } else if (!fstab_directory_iterator.has_error()) {
         while (fstab_directory_iterator.has_next()) {
             auto path = fstab_directory_iterator.next_full_path();

Userland/Utilities/sysctl.cpp

@@ -82,7 +82,7 @@ static int handle_show_all()
 {
     Core::DirIterator di("/sys/kernel/variables", Core::DirIterator::SkipDots);
     if (di.has_error()) {
-        outln("DirIterator: {}", di.error_string());
+        outln("DirIterator: {}", di.error());
         return 1;
     }
 

Userland/Utilities/tree.cpp

@@ -48,7 +48,7 @@ static void print_directory_tree(DeprecatedString const& root_path, int depth, D
 
     Core::DirIterator di(root_path, flag_show_hidden_files ? Core::DirIterator::SkipParentAndBaseDir : Core::DirIterator::SkipDots);
     if (di.has_error()) {
-        warnln("{}: {}", root_path, di.error_string());
+        warnln("{}: {}", root_path, di.error());
         return;
     }
 
@@ -56,7 +56,7 @@ static void print_directory_tree(DeprecatedString const& root_path, int depth, D
     while (di.has_next()) {
         DeprecatedString name = di.next_path();
         if (di.has_error()) {
-            warnln("{}: {}", root_path, di.error_string());
+            warnln("{}: {}", root_path, di.error());
             continue;
         }
         names.append(name);