diff --git a/apps/src/sh.c b/apps/src/sh.c
index 0b229810..9e605f31 100644
--- a/apps/src/sh.c
+++ b/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;
-    long capacity;
+    size_t size;
+    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)
     {