Utilities: Use Vector<String> positional arguments in some places

There are more places we can use these, I just picked some that felt
like they improved the code.

Userland/Utilities/cat.cpp

@@ -6,13 +6,11 @@
 
 #include <AK/Vector.h>
 #include <LibCore/ArgsParser.h>
-#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/stat.h>
 #include <unistd.h>
 
 int main(int argc, char** argv)
@@ -22,7 +20,7 @@ int main(int argc, char** argv)
         return 1;
     }
 
-    Vector<const char*> paths;
+    Vector<String> paths;
 
     Core::ArgsParser args_parser;
     args_parser.set_general_help("Concatenate files or pipes to stdout.");
@@ -31,12 +29,12 @@ int main(int argc, char** argv)
 
     Vector<int> fds;
     if (!paths.is_empty()) {
-        for (const char* path : paths) {
+        for (auto const& path : paths) {
             int fd;
-            if (StringView { path } == "-") {
+            if (path == "-") {
                 fd = 0;
-            } else if ((fd = open(path, O_RDONLY)) == -1) {
+            } else if ((fd = open(path.characters(), O_RDONLY)) == -1) {
-                fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
+                warnln("Failed to open {}: {}", path, strerror(errno));
                 continue;
             }
             fds.append(fd);

Userland/Utilities/checksum.cpp

@@ -36,7 +36,7 @@ int main(int argc, char** argv)
     auto hash_name = program_name.substring_view(0, program_name.length() - 3).to_string().to_uppercase();
     auto paths_help_string = String::formatted("File(s) to print {} checksum of", hash_name);
 
-    Vector<const char*> paths;
+    Vector<String> paths;
 
     Core::ArgsParser args_parser;
     args_parser.add_positional_argument(paths, paths_help_string.characters(), "path", Core::ArgsParser::Required::No);
@@ -52,8 +52,8 @@ int main(int argc, char** argv)
     auto has_error = false;
     auto file = Core::File::construct();
 
-    for (auto path : paths) {
+    for (auto const& path : paths) {
-        if (StringView { path } == "-") {
+        if (path == "-") {
             success = file->open(STDIN_FILENO, Core::IODevice::OpenMode::ReadOnly, Core::File::ShouldCloseFileDescriptor::No);
         } else {
             file->set_filename(path);

Userland/Utilities/gunzip.cpp

@@ -25,7 +25,7 @@ static bool decompress_file(Buffered<Core::InputFileStream>& input_stream, Buffe
 
 int main(int argc, char** argv)
 {
-    Vector<const char*> filenames;
+    Vector<String> filenames;
     bool keep_input_files { false };
     bool write_to_stdout { false };
 
@@ -38,7 +38,7 @@ int main(int argc, char** argv)
     if (write_to_stdout)
         keep_input_files = true;
 
-    for (String filename : filenames) {
+    for (auto filename : filenames) {
         if (!filename.ends_with(".gz"))
             filename = String::formatted("{}.gz", filename);
 

Userland/Utilities/gzip.cpp

@@ -12,7 +12,7 @@
 
 int main(int argc, char** argv)
 {
-    Vector<const char*> filenames;
+    Vector<String> filenames;
     bool keep_input_files { false };
     bool write_to_stdout { false };
 
@@ -25,7 +25,7 @@ int main(int argc, char** argv)
     if (write_to_stdout)
         keep_input_files = true;
 
-    for (const String input_filename : filenames) {
+    for (auto const& input_filename : filenames) {
         auto output_filename = String::formatted("{}.gz", input_filename);
 
         // We map the whole file instead of streaming to reduce size overhead (gzip header) and increase the deflate block size (better compression)

Userland/Utilities/tar.cpp

@@ -175,7 +175,7 @@ int main(int argc, char** argv)
             }
         };
 
-        for (const String path : paths) {
+        for (auto const& path : paths) {
             if (Core::File::is_directory(path)) {
                 add_directory(path, add_directory);
             } else {

Userland/Utilities/zip.cpp

@@ -16,7 +16,7 @@
 int main(int argc, char** argv)
 {
     const char* zip_path;
-    Vector<const char*> source_paths;
+    Vector<String> source_paths;
     bool recurse = false;
     bool force = false;
 
@@ -104,7 +104,7 @@ int main(int argc, char** argv)
         }
     };
 
-    for (const String source_path : source_paths) {
+    for (auto const& source_path : source_paths) {
         if (Core::File::is_directory(source_path)) {
             add_directory(source_path, add_directory);
         } else {