diff --git a/sh.c b/sh.c
index d207f61..bafcaa2 100755
--- a/sh.c
+++ b/sh.c
@@ -5,13 +5,13 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/wait.h>
+#include <sys/stat.h>
 #include <signal.h>
 #include <libgen.h>
 #include <errno.h>
 #include <limits.h>
 
 #define ARG_SEP " " /* Argument separator for commands */
-#define PROMPT " $ "
 
 char** create_argv(char* command);
 int get_argc(char* command);
@@ -20,11 +20,17 @@ char* prompt();
 int cd(char* path);
 int _kill(int argc, char * argv[]);
 
+mode_t _umask = 022;
+char * prompt_str;
+#define PROMPT prompt_str
+
 int main() {
   char** argv;
   char* user_input;
   pid_t child_pid;
   int stat_loc; /* ??? (Needed for waitpid) */
+  prompt_str = getenv("PS1");
+  prompt_str = prompt_str == NULL ? "$ " : prompt_str;
 
   signal(SIGINT, SIG_IGN);
 
@@ -47,6 +53,20 @@ int main() {
       strcmp(argv[0], "quit") == 0) {
       exit(0);
     }
+    else if(strcmp(argv[0], "umask") == 0) {
+      if(strcmp(argv[1], "-S") == 0) {
+        /* TODO: Print symbolic string. */
+      }
+      else if(argv[1] != NULL) {
+        /* TODO: Implement symbolic support. */
+        _umask = atoi(argv[1]);
+        umask(_umask);
+      }
+      else {
+        printf("%o\n", _umask);
+      }
+      continue;
+    }
 
     child_pid = fork();
     if(child_pid < 0) {