From 25a2a4879c2593ade940f63c67853ed4cd5c04c1 Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Sun, 11 Jun 2023 03:29:41 +0300
Subject: [PATCH] Userspace: add basic ls command

---
 userspace/CMakeLists.txt    |   3 +-
 userspace/ls/CMakeLists.txt |  16 ++++
 userspace/ls/main.cpp       | 144 ++++++++++++++++++++++++++++++++++++
 3 files changed, 162 insertions(+), 1 deletion(-)
 create mode 100644 userspace/ls/CMakeLists.txt
 create mode 100644 userspace/ls/main.cpp

diff --git a/userspace/CMakeLists.txt b/userspace/CMakeLists.txt
index 65ee48c6..16d090a5 100644
--- a/userspace/CMakeLists.txt
+++ b/userspace/CMakeLists.txt
@@ -3,9 +3,10 @@ cmake_minimum_required(VERSION 3.26)
 project(userspace CXX)
 
 set(USERSPACE_PROJECTS
-	Shell
 	cat
 	echo
+	ls
+	Shell
 	test
 	yes
 )
diff --git a/userspace/ls/CMakeLists.txt b/userspace/ls/CMakeLists.txt
new file mode 100644
index 00000000..df6d503d
--- /dev/null
+++ b/userspace/ls/CMakeLists.txt
@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.26)
+
+project(ls CXX)
+
+set(SOURCES
+	main.cpp
+)
+
+add_executable(ls ${SOURCES})
+target_compile_options(ls PUBLIC -O2 -g)
+target_link_libraries(ls PUBLIC libc)
+
+add_custom_target(ls-install
+	COMMAND cp ${CMAKE_CURRENT_BINARY_DIR}/ls ${BANAN_BIN}/
+	DEPENDS ls
+)
diff --git a/userspace/ls/main.cpp b/userspace/ls/main.cpp
new file mode 100644
index 00000000..db113e6d
--- /dev/null
+++ b/userspace/ls/main.cpp
@@ -0,0 +1,144 @@
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+
+bool all { false };
+bool list { false };
+
+const char* mode_string(mode_t mode)
+{
+	static char buffer[11];
+	buffer[0] =	(mode & 0770000) == S_IFLNK ? 'l' :
+				(mode & 0770000) == S_IFDIR ? 'd' :
+				(mode & 0770000) == S_IFBLK ? 'b' :
+				(mode & 0770000) == S_IFCHR ? 'c' :
+				'-';
+	buffer[1] = mode & S_IRUSR ? 'r' : '-';
+	buffer[2] = mode & S_IWUSR ? 'w' : '-';
+	buffer[3] = mode & S_IXUSR ? 'x' : '-';
+	buffer[4] = mode & S_IRGRP ? 'r' : '-';
+	buffer[5] = mode & S_IWGRP ? 'w' : '-';
+	buffer[6] = mode & S_IXGRP ? 'x' : '-';
+	buffer[7] = mode & S_IROTH ? 'r' : '-';
+	buffer[8] = mode & S_IWOTH ? 'w' : '-';
+	buffer[9] = mode & S_IXOTH ? 'x' : '-';
+	buffer[10] = '\0';
+
+	return buffer;
+}
+
+void list_directory(const char* path)
+{
+	DIR* dirp = opendir(path);
+	if (dirp == nullptr)
+		return perror("opendir");
+	
+	errno = 0;
+	
+	bool first = true;
+	while (auto* dirent = readdir(dirp))
+	{
+		if (!all && dirent->d_name[0] == '.')
+			continue;
+
+		if (list)
+		{
+			if (!first)
+				printf("\n");
+
+			struct stat st;
+			if (fstatat(dirfd(dirp), dirent->d_name, &st, AT_SYMLINK_NOFOLLOW) == -1)
+			{
+				perror("stat");
+				printf("?????????? ???? %s", dirent->d_name);
+			}
+			else
+			{
+				printf("%s %d %s", mode_string(st.st_mode), st.st_size, dirent->d_name);
+			}
+		}
+		else
+		{
+			if (!first)
+				printf(" ");
+			printf("%s", dirent->d_name);
+		}
+
+		first = false;
+	}
+
+	if (errno != 0)
+		perror("readdir");
+
+	printf("\n");
+
+	closedir(dirp);
+}
+
+void print_usage()
+{
+	printf("Usage: ls [OPTION]... [FILE]...\n");
+	printf("  -a, --all     show all files\n");
+	printf("  -l, --list    print files on separate lines\n");
+}
+
+int main(int argc, char** argv)
+{
+	int arg = 1;
+
+	while (arg < argc && argv[arg][0] == '-')
+	{
+		if (strcmp(argv[arg], "--all") == 0)
+			all = true;
+		else if (strcmp(argv[arg], "--list") == 0)
+			list = true;
+		else if (strcmp(argv[arg], "--help") == 0)
+		{
+			print_usage();
+			return 0;
+		}
+		else
+		{
+			for (int i = 1; argv[arg][i]; i++)
+			{
+				char c = argv[arg][i];
+				if (c == 'a')
+					all = true;
+				else if (c == 'l')
+					list = true;
+				else
+				{
+					print_usage();
+					return 1;
+				}
+			}
+		}
+
+		arg++;
+	}
+
+	if (arg == argc)
+	{
+		list_directory(".");
+	}
+	else if (arg + 1 == argc)
+	{
+		list_directory(argv[arg]);
+	}
+	else
+	{
+		for (int i = arg; i < argc; i++)
+		{
+			if (i > arg)
+				printf("\n");
+			printf("%s:\n", argv[i]);
+			list_directory(argv[i]);
+		}
+	}
+
+	return 0;
+}