Initial Upload

init.c

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+// init: The initial user-level program
+
+#include "types.h"
+#include "stat.h"
+#include "user.h"
+#include "fcntl.h"
+
+char *argv[] = { "sh", 0 };
+
+int main(void) {
+    int pid, wpid;
+
+    if (open("console", O_RDWR) < 0) {
+        mknod("console", 1, 1);
+        open("console", O_RDWR);
+    }
+    dup(0);  // stdout
+    dup(0);  // stderr
+
+    for (;;) {
+        printf(1, "init: starting sh\n");
+        pid = fork();
+        if (pid < 0) {
+            printf(1, "init: fork failed\n");
+            exit();
+        }
+        if (pid == 0) {
+            exec("sh", argv);
+            printf(1, "init: exec sh failed\n");
+            exit();
+        }
+        while ((wpid = wait()) >= 0 && wpid != pid) {
+        }
+    }
+}