sh: add builtins

apps/src/init.c

@@ -67,11 +67,14 @@ int main()
         return 1;
     }
 
+    pid_t result;
+
     for (;;)
     {
-        while (wait(NULL) == 0) // No child has exited yet
+        while ((result = wait(NULL)) == 0) // No child has exited yet
         {
             msleep(100);
         }
+        if (result == child) { return 0; }
     }
 }

apps/src/sh.c

@@ -1,6 +1,7 @@
 #include <luna.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
@@ -9,8 +10,8 @@ static int status;
 typedef struct
 {
     char* buffer;
-    long size;
+    size_t size;
-    long capacity;
+    size_t capacity;
 } command;
 
 void show_prompt()
@@ -18,6 +19,33 @@ void show_prompt()
     printf("[%ld]> ", getpid());
 }
 
+int command_matches(command* cmd, const char* string)
+{
+    if (cmd->size <= strlen(string)) // cmd->size includes null terminator
+        return 0;
+    return strncmp(cmd->buffer, string, strlen(string)) == 0;
+}
+
+int command_matches_exactly(command* cmd, const char* string)
+{
+    if (cmd->size <= strlen(string)) // cmd->size includes null terminator
+        return 0;
+    if (cmd->size > (strlen(string) + 1)) return 0;
+    return strncmp(cmd->buffer, string, strlen(string)) == 0;
+}
+
+int command_match_builtins(command* cmd)
+{
+    if (command_matches(cmd, "exit ")) { exit(atoi(cmd->buffer + 5)); }
+    if (command_matches_exactly(cmd, "exit")) { exit(0); }
+    if (command_matches_exactly(cmd, "pid"))
+    {
+        printf("pid %ld, ppid %ld\n", getpid(), getppid());
+        return 1;
+    }
+    return 0;
+}
+
 void command_expand(command* cmd, long new_capacity)
 {
     char* buffer = realloc(cmd->buffer, new_capacity);
@@ -58,6 +86,12 @@ void command_clear(command* cmd)
 void command_execute(command* cmd)
 {
     command_push(cmd, '\0');
+    if (command_match_builtins(cmd))
+    {
+        command_clear(cmd);
+        show_prompt();
+        return;
+    }
     pid_t child = fork();
     if (child < 0)
     {

kernel/src/thread/Scheduler.cpp

@@ -7,6 +7,7 @@
 #include "memory/PMM.h"
 #include "memory/VMM.h"
 #include "misc/hang.h"
+#include "misc/reboot.h"
 #include "misc/utils.h"
 #include "panic/Panic.h"
 #include "std/assert.h"
@@ -280,6 +281,7 @@ void Scheduler::task_exit(Context* context, int64_t status)
             return true;
         });
     }
+    else { reboot(); }
     task_yield(context);
 }
 
@@ -298,6 +300,7 @@ void Scheduler::task_misbehave(Context* context, int64_t status)
             return true;
         });
     }
+    else { reboot(); }
     task_yield(context);
 }