Utilities: Add a pdf utility

This utility will learn tricks such as extracting images from PDFs and
dumping tables from PDFs so that we can create code from specs.

It also allows testing LibPDF things in lagom, and allows testing
reading large amounts of PDFs using a shell script.

Meta/Lagom/CMakeLists.txt

@@ -555,6 +555,9 @@ if (BUILD_LAGOM)
             target_link_libraries(ntpquery LibCore LibMain)
         endif()
 
+        add_executable(pdf ../../Userland/Utilities/pdf.cpp)
+        target_link_libraries(pdf LibCore LibPDF LibMain)
+
         add_executable(sql ../../Userland/Utilities/sql.cpp)
         target_link_libraries(sql LibCore LibFileSystem LibIPC LibLine LibMain LibSQL)
 

Userland/Utilities/CMakeLists.txt

@@ -123,6 +123,7 @@ target_link_libraries(notify PRIVATE LibGfx LibGUI)
 target_link_libraries(open PRIVATE LibDesktop LibFileSystem)
 target_link_libraries(passwd PRIVATE LibCrypt)
 target_link_libraries(paste PRIVATE LibGUI)
+target_link_libraries(pdf PRIVATE LibPDF)
 target_link_libraries(pgrep PRIVATE LibRegex)
 target_link_libraries(pixelflut PRIVATE LibImageDecoderClient LibIPC LibGfx)
 target_link_libraries(pkill PRIVATE LibRegex)

Userland/Utilities/pdf.cpp

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2023, Nico Weber <thakis@chromium.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibCore/ArgsParser.h>
+#include <LibCore/File.h>
+#include <LibCore/MappedFile.h>
+#include <LibPDF/Document.h>
+
+static PDF::PDFErrorOr<int> pdf_main(Main::Arguments arguments)
+{
+    Core::ArgsParser args_parser;
+
+    StringView in_path;
+    args_parser.add_positional_argument(in_path, "Path to input image file", "FILE");
+
+    args_parser.parse(arguments);
+
+    auto file = TRY(Core::MappedFile::map(in_path));
+
+    auto document = TRY(PDF::Document::create(file->bytes()));
+
+    if (auto handler = document->security_handler(); handler && !handler->has_user_password()) {
+        // FIXME: Add a flag for passing in a password and suggest it in this diag.
+        warnln("PDF requires password");
+        return 1;
+    }
+
+    TRY(document->initialize());
+
+    outln("{} pages", document->get_page_count());
+
+    return 0;
+}
+
+ErrorOr<int> serenity_main(Main::Arguments arguments)
+{
+    auto maybe_error = pdf_main(move(arguments));
+    if (maybe_error.is_error()) {
+        auto error = maybe_error.release_error();
+        warnln("{}", error.message());
+        return 1;
+    }
+    return 0;
+}