Kernel/LibC: add SYS_STAT and stat(), lstat()

kernel/include/kernel/Process.h

@@ -64,7 +64,7 @@ namespace Kernel
 		BAN::ErrorOr<off_t> tell(int fd);
 
 		BAN::ErrorOr<void> fstat(int fd, struct stat*);
-		BAN::ErrorOr<void> stat(BAN::StringView path, struct stat*);
+		BAN::ErrorOr<void> stat(BAN::StringView path, struct stat*, int flags);
 
 		BAN::ErrorOr<void> mount(BAN::StringView source, BAN::StringView target);
 

kernel/kernel/Process.cpp

@@ -522,9 +522,9 @@ namespace Kernel
 		return {};
 	}
 
-	BAN::ErrorOr<void> Process::stat(BAN::StringView path, struct stat* out)
+	BAN::ErrorOr<void> Process::stat(BAN::StringView path, struct stat* out, int flags)
 	{
-		int fd = TRY(open(path, O_RDONLY | O_NOFOLLOW));
+		int fd = TRY(open(path, flags));
 		auto ret = fstat(fd, out);
 		MUST(close(fd));
 		return ret;

kernel/kernel/Shell.cpp

@@ -534,7 +534,7 @@ argument_done:
 				BAN::String entry_path;
 				TRY(entry_path.append(entry_prefix));
 				TRY(entry_path.append(entry));
-				TRY(Process::current().stat(entry_path, &st));
+				TRY(Process::current().stat(entry_path, &st, O_RDONLY | O_NOFOLLOW));
 
 				Inode::Mode mode { st.st_mode };
 
@@ -577,7 +577,7 @@ argument_done:
 			}
 			
 			struct stat st;
-			TRY(Process::current().stat(arguments[1], &st));
+			TRY(Process::current().stat(arguments[1], &st, O_RDONLY | O_NOFOLLOW));
 
 			Inode::Mode mode { st.st_mode };
 

kernel/kernel/Syscall.cpp

@@ -128,6 +128,14 @@ namespace Kernel
 		return ret.value();
 	}
 
+	long sys_stat(const char* path, struct stat* buf, int flags)
+	{
+		auto ret = Process::current().stat(path, buf, flags);
+		if (ret.is_error())
+			return -ret.error().get_error_code();
+		return 0;
+	}
+
 	extern "C" long sys_fork_trampoline();
 
 	extern "C" long cpp_syscall_handler(int syscall, uintptr_t arg1, uintptr_t arg2, uintptr_t arg3, uintptr_t arg4, uintptr_t arg5)
@@ -193,6 +201,9 @@ namespace Kernel
 		case SYS_WAIT:
 			ret = sys_wait((pid_t)arg1, (int*)arg2, (int)arg3);
 			break;
+		case SYS_STAT:
+			ret = sys_stat((const char*)arg1, (struct stat*)arg2, (int)arg3);
+			break;
 		default:
 			Kernel::panic("Unknown syscall {}", syscall);
 		}

kernel/kernel/kernel.cpp

@@ -180,8 +180,8 @@ static void init2(void* tty1)
 
 	((TTY*)tty1)->initialize_device();
 
-	//MUST(Process::create_userspace("/usr/bin/test"sv));
-	//return;
+	MUST(Process::create_userspace("/usr/bin/Shell"sv));
+	return;
 
 	Process::create_kernel(
 		[](void*) 

libc/CMakeLists.txt

@@ -10,6 +10,7 @@ set(LIBC_SOURCES
 	stdio.cpp
 	stdlib.cpp
 	string.cpp
+	sys/stat.cpp
 	sys/wait.cpp
 	termios.cpp
 	unistd.cpp

libc/include/sys/syscall.h

@@ -22,6 +22,7 @@ __BEGIN_DECLS
 #define SYS_EXEC 15
 #define SYS_REALLOC 16
 #define SYS_WAIT 17
+#define SYS_STAT 18
 
 __END_DECLS
 

libc/sys/stat.cpp

@@ -0,0 +1,14 @@
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+int lstat(const char* __restrict path, struct stat* __restrict buf)
+{
+    return syscall(SYS_STAT, path, buf, O_RDONLY | O_NOFOLLOW);
+}
+
+int stat(const char* __restrict path, struct stat* __restrict buf)
+{
+    return syscall(SYS_STAT, path, buf, O_RDONLY);
+}

libc/unistd.cpp

@@ -5,6 +5,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/stat.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 
@@ -145,6 +146,14 @@ long syscall(long syscall, ...)
 			ret = Kernel::syscall(SYS_WAIT, pid, (uintptr_t)stat_loc, options);
 			break;
 		}
+		case SYS_STAT:
+		{
+			const char* path = va_arg(args, const char*);
+			struct stat* buf = va_arg(args, struct stat*);
+			int flags = va_arg(args, int);
+			ret = Kernel::syscall(SYS_STAT, (uintptr_t)path, (uintptr_t)buf, flags);
+			break;
+		}
 		default:
 			puts("LibC: Unhandeled syscall");
 			ret = -ENOSYS;

userspace/Shell/main.cpp

@@ -1,6 +1,7 @@
 #include <BAN/ScopeGuard.h>
 #include <BAN/String.h>
 #include <BAN/Vector.h>
+#include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/stat.h>
@@ -42,6 +43,13 @@ int execute_command(BAN::StringView command)
 	}
 	else
 	{
+		struct stat stat_buf;
+		if (stat(args.front(), &stat_buf) == -1)
+		{
+			fprintf(stderr, "command not found: %s\n", args.front());
+			return 1;
+		}
+
 		pid_t pid = fork();
 		if (pid == 0)
 		{
@@ -63,6 +71,28 @@ int execute_command(BAN::StringView command)
 	return 0;
 }
 
+int prompt_length(BAN::StringView prompt)
+{
+	int length { 0 };
+	bool in_escape { false };
+	for (char c : prompt)
+	{
+		if (in_escape)
+		{
+			if (isalpha(c))
+				in_escape = false;
+		}
+		else
+		{
+			if (c == '\e')
+				in_escape = true;
+			else
+				length++;
+		}
+	}
+	return length;
+}
+
 int main(int argc, char** argv)
 {
 	tcgetattr(0, &old_termios);
@@ -102,8 +132,8 @@ int main(int argc, char** argv)
 			fread(&c, 1, sizeof(char), stdin);
 			switch (c)
 			{
-				case 'A': if (index > 0)					{ index--; col = buffers[index].size(); fprintf(stdout, "\e[G%s\e[K", buffers[index].data()); fflush(stdout); } break;
-				case 'B': if (index < buffers.size() - 1)	{ index++; col = buffers[index].size(); fprintf(stdout, "\e[G%s\e[K", buffers[index].data()); fflush(stdout); } break;
+				case 'A': if (index > 0)					{ index--; col = buffers[index].size(); fprintf(stdout, "\e[%dG%s\e[K", prompt_length(prompt) + 1, buffers[index].data()); fflush(stdout); } break;
+				case 'B': if (index < buffers.size() - 1)	{ index++; col = buffers[index].size(); fprintf(stdout, "\e[%dG%s\e[K", prompt_length(prompt) + 1, buffers[index].data()); fflush(stdout); } break;
 				case 'C': break;
 				case 'D': break;
 			}