libos: Add a Process class

apps/sh.cpp

@@ -3,6 +3,7 @@
 #include <os/ArgumentParser.h>
 #include <os/File.h>
 #include <os/FileSystem.h>
+#include <os/Process.h>
 
 #include <errno.h>
 #include <stddef.h>
@@ -113,12 +114,7 @@ Result<int> luna_main(int argc, char** argv)
             continue;
         }
 
-        pid_t child = fork();
-        if (child < 0)
-        {
-            perror("fork");
-            return 1;
-        }
+        pid_t child = TRY(os::Process::fork());
 
         if (child == 0) { execute_command(cmd.view()); }
 

libos/CMakeLists.txt

@@ -7,6 +7,7 @@ set(SOURCES
     src/ArgumentParser.cpp
     src/File.cpp
     src/FileSystem.cpp
+    src/Process.cpp
     src/Main.cpp
 )
 

libos/include/os/Process.h

@@ -0,0 +1,12 @@
+#pragma once
+#include <luna/Result.h>
+#include <sys/types.h>
+
+namespace os
+{
+    class Process
+    {
+      public:
+        static Result<pid_t> fork();
+    };
+}

libos/src/Process.cpp

@@ -0,0 +1,12 @@
+#include <os/Process.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+namespace os
+{
+    Result<pid_t> Process::fork()
+    {
+        long rc = syscall(SYS_fork);
+        return Result<pid_t>::from_syscall(rc);
+    }
+}