Add --recursive and --dereference-recursive.

Closes: #5

man/epubgrep.1.adoc

@@ -2,7 +2,7 @@
 :doctype:       manpage
 :Author:        tastytea
 :Email:         tastytea@tastytea.de
-:Date:          2021-05-26
+:Date:          2021-05-27
 :Revision:      0.0.0
 :man source:    epubgrep
 :man manual:    General Commands Manual
@@ -61,6 +61,14 @@ Do not color matches.
 *--no-filename*::
 Suppress the mentioning of file names on output. Chapters and page numbers will
 still be output.
+*-r*, *--recursive*:
+Read all files under each directory, recursively, following symbolic links only
+if they are on the command line. Silently skips directories that are not
+readable by the user.
+
+*-R*, *--dereference-recursive*
+Read all files under each directory, recursively. Follow all symbolic
+links. Silently skips directories that are not readable by the user.
 
 == USAGE
 

src/files.cpp

@@ -0,0 +1,52 @@
+/*  This file is part of epubgrep.
+ *  Copyright © 2021 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "files.hpp"
+
+#include "fs-compat.hpp"
+
+#include <exception>
+#include <iostream>
+#include <string_view>
+#include <vector>
+
+namespace epubgrep::files
+{
+
+std::vector<fs::path> list_recursive(const fs::path &directory,
+                                     const bool follow_symlinks)
+{
+    fs::directory_options dir_options{
+        fs::directory_options::skip_permission_denied};
+    if (follow_symlinks)
+    {
+        dir_options |= fs::directory_options::follow_directory_symlink;
+    }
+    fs::recursive_directory_iterator dir_iter{directory, dir_options};
+
+    std::vector<fs::path> paths;
+    for (const auto &path : dir_iter)
+    {
+        if (!path.is_directory())
+        {
+            paths.emplace_back(path);
+        }
+    }
+
+    return paths;
+}
+
+} // namespace epubgrep::files

src/files.hpp

@@ -0,0 +1,34 @@
+/*  This file is part of epubgrep.
+ *  Copyright © 2021 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef EPUBGREP_FILES_HPP
+#define EPUBGREP_FILES_HPP
+
+#include "fs-compat.hpp"
+
+#include <string_view>
+#include <vector>
+
+namespace epubgrep::files
+{
+
+//! List files in directory recursively.
+[[nodiscard]] std::vector<fs::path> list_recursive(const fs::path &directory,
+                                                   bool follow_symlinks);
+
+} // namespace epubgrep::files
+
+#endif // EPUBGREP_FILES_HPP

src/main.cpp

@@ -14,6 +14,8 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "files.hpp"
+#include "fs-compat.hpp"
 #include "options.hpp"
 #include "search.hpp"
 
@@ -78,6 +80,8 @@ int main(int argc, char *argv[])
         return EXIT_SUCCESS;
     }
 
+    int return_code{EXIT_SUCCESS};
+
     vector<fs::path> input_files;
     if (vm.count("input-file") == 0)
     {
@@ -87,10 +91,44 @@ int main(int argc, char *argv[])
     }
     for (const auto &filepath : vm["input-file"].as<vector<string>>())
     {
-        input_files.emplace_back(filepath);
+        if (vm.count("recursive") + vm.count("dereference-recursive") == 0)
-    }
+        {
 
-    int return_code{EXIT_SUCCESS};
+            input_files.emplace_back(filepath);
+        }
+        else
+        {
+            bool follow_symlinks{false};
+            if (vm.count("dereference-recursive") > 0)
+            {
+                follow_symlinks = true;
+            }
+
+            try
+            {
+                auto files_in_dir{
+                    files::list_recursive(filepath, follow_symlinks)};
+                input_files.insert(input_files.end(), files_in_dir.begin(),
+                                   files_in_dir.end());
+            }
+            catch (const fs::filesystem_error &e)
+            {
+                if (e.code().value() == 20)
+                { // Is not a directory.
+                    input_files.emplace_back(filepath);
+                    continue;
+                }
+
+                cerr << '\n'
+                     << format(translate("ERROR: Could not open {0:s}: {1:s}")
+                                   .str()
+                                   .data(),
+                               e.path1(), e.what())
+                     << '\n';
+                return_code = EXIT_FAILURE;
+            }
+        }
+    }
 
     search::options opts;
     if (vm.count("basic-regexp") > 0)

src/options.cpp

@@ -76,6 +76,12 @@ po::variables_map parse_options(int argc, char *argv[])
         ("no-filename",
          translate("Suppress the mentioning of file names on output.")
          .str().data())
+        ("recursive,r",
+         translate("Read all files under each directory, recursively.")
+         .str().data())
+        ("dereference-recursive,R",
+         translate("Read all files under each directory, recursively, "
+                   "following symlinks.") .str().data())
     ;
 
     po::options_description options_hidden("Hidden options");