From 0a02c7a926928f2e8d7e2e62df4a12e566e0a7fb Mon Sep 17 00:00:00 2001
From: Tim Ledbetter <timledbetter@gmail.com>
Date: Sun, 27 Aug 2023 16:46:31 +0100
Subject: [PATCH] find: Add the `-regex` and `-iregex` options

These options match a given regular expression against the whole file
path. `-iregex` is identical to `-regex` except it is case-insensitive.
---
 Userland/Utilities/CMakeLists.txt |  1 +
 Userland/Utilities/find.cpp       | 33 +++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/Userland/Utilities/CMakeLists.txt b/Userland/Utilities/CMakeLists.txt
index cf63c82563..3b378a6a04 100644
--- a/Userland/Utilities/CMakeLists.txt
+++ b/Userland/Utilities/CMakeLists.txt
@@ -92,6 +92,7 @@ target_link_libraries(disasm PRIVATE LibX86)
 target_link_libraries(expr PRIVATE LibRegex)
 target_link_libraries(fdtdump PRIVATE LibDeviceTree)
 target_link_libraries(file PRIVATE LibGfx LibIPC LibArchive LibCompress LibAudio)
+target_link_libraries(find PRIVATE LibRegex)
 target_link_libraries(functrace PRIVATE LibDebug LibX86)
 target_link_libraries(glsl-compiler PRIVATE LibGLSL)
 target_link_libraries(gml-format PRIVATE LibGUI)
diff --git a/Userland/Utilities/find.cpp b/Userland/Utilities/find.cpp
index c75c31fc41..0727d2a507 100644
--- a/Userland/Utilities/find.cpp
+++ b/Userland/Utilities/find.cpp
@@ -12,6 +12,7 @@
 #include <AK/Vector.h>
 #include <LibCore/System.h>
 #include <LibMain/Main.h>
+#include <LibRegex/Regex.h>
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -267,6 +268,24 @@ private:
     CaseSensitivity m_case_sensitivity { CaseSensitivity::CaseSensitive };
 };
 
+class RegexCommand : public Command {
+public:
+    RegexCommand(Regex<PosixBasic>&& regex)
+        : m_regex(move(regex))
+    {
+    }
+
+private:
+    virtual bool evaluate(FileData& file_data) const override
+    {
+        auto haystack = file_data.full_path.string();
+        auto match_result = m_regex.match(haystack);
+        return match_result.success;
+    }
+
+    Regex<PosixBasic> m_regex;
+};
+
 class AccessCommand final : public Command {
 public:
     AccessCommand(mode_t mode)
@@ -426,6 +445,20 @@ static OwnPtr<Command> parse_simple_command(Vector<char*>& args)
         if (args.is_empty())
             fatal_error("-iname: requires additional arguments");
         return make<NameCommand>(args.take_first(), CaseSensitivity::CaseInsensitive);
+    } else if (arg == "-regex") {
+        if (args.is_empty())
+            fatal_error("-regex: requires additional arguments");
+        Regex<PosixBasic> regex { args.take_first(), PosixFlags::Default };
+        if (regex.parser_result.error != regex::Error::NoError)
+            fatal_error("{}", regex.error_string());
+        return make<RegexCommand>(move(regex));
+    } else if (arg == "-iregex") {
+        if (args.is_empty())
+            fatal_error("-iregex: requires additional arguments");
+        Regex<PosixBasic> regex { args.take_first(), PosixFlags::Insensitive };
+        if (regex.parser_result.error != regex::Error::NoError)
+            fatal_error("{}", regex.error_string());
+        return make<RegexCommand>(move(regex));
     } else if (arg == "-readable") {
         return make<AccessCommand>(R_OK);
     } else if (arg == "-writable") {