userland: move getchar from cpp-cheat

userland/c/getchar.c

@@ -0,0 +1,21 @@
+/* Get on character from stdin, and then print it back out.
+ *
+ * Same as getc(stdin).
+ *
+ * You have to press enter for the character to go through:
+ * https://stackoverflow.com/questions/1798511/how-to-avoid-pressing-enter-with-getchar
+ *
+ * Used at:
+ * https://stackoverflow.com/questions/556405/what-do-real-user-and-sys-mean-in-the-output-of-time1/53937376#53937376
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+    char c;
+    printf("enter a character: ");
+    c = getchar();
+    printf("you entered: %c\n", c);
+    return EXIT_SUCCESS;
+}