cksum: Stop using DeprecatedString

This has the side-effect of making the algorithm name case-sensitive,
but there doesn't seem to be an especially good reason to support that.
On the other hand, converting an AK::String to lowercase would require
linking LibUnicode.

Userland/Utilities/cksum.cpp

@@ -4,9 +4,9 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/String.h>
 #include <LibCore/ArgsParser.h>
 #include <LibCore/File.h>
-#include <LibCore/System.h>
 #include <LibCrypto/Checksum/Adler32.h>
 #include <LibCrypto/Checksum/CRC32.h>
 #include <LibMain/Main.h>
@@ -14,7 +14,7 @@
 
 ErrorOr<int> serenity_main(Main::Arguments arguments)
 {
-    Vector<DeprecatedString> paths;
+    Vector<StringView> paths;
     StringView opt_algorithm;
 
     Core::ArgsParser args_parser;
@@ -22,9 +22,9 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     args_parser.add_positional_argument(paths, "File", "file", Core::ArgsParser::Required::No);
     args_parser.parse(arguments);
 
-    auto algorithm = opt_algorithm.is_empty() ? "crc32" : DeprecatedString(opt_algorithm).to_lowercase();
+    auto algorithm = opt_algorithm.is_empty() ? "crc32"sv : opt_algorithm;
 
-    auto available_algorithms = Vector<DeprecatedString> { "crc32", "adler32" };
+    auto available_algorithms = Vector<StringView> { "crc32"sv, "adler32"sv };
 
     if (algorithm == "list") {
         outln("Available algorithms:");
@@ -40,14 +40,14 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     }
 
     if (paths.is_empty())
-        paths.append("-");
+        paths.append("-"sv);
 
     bool fail = false;
     Array<u8, PAGE_SIZE> buffer;
 
     for (auto& path : paths) {
         auto file_or_error = Core::File::open_file_or_standard_stream(path, Core::File::OpenMode::Read);
-        auto filepath = (path == "-") ? "/dev/stdin" : path;
+        auto filepath = (path == "-"sv) ? "/dev/stdin"sv : path;
         if (file_or_error.is_error()) {
             warnln("{}: {}: {}", arguments.strings[0], filepath, file_or_error.error());
             fail = true;
@@ -56,7 +56,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         auto file = file_or_error.release_value();
         size_t file_size = 0;
 
-        if (algorithm == "crc32") {
+        if (algorithm == "crc32"sv) {
             Crypto::Checksum::CRC32 crc32;
             while (!file->is_eof()) {
                 auto data_or_error = file->read_some(buffer);
@@ -69,7 +69,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
                 crc32.update(data_or_error.value());
             }
             outln("{:08x} {} {}", crc32.digest(), file_size, path);
-        } else if (algorithm == "adler32") {
+        } else if (algorithm == "adler32"sv) {
             Crypto::Checksum::Adler32 adler32;
             while (!file->is_eof()) {
                 auto data_or_error = file->read_some(buffer);