caesar passes check50 but won't run from command line

Question

My caesar code compiles and passes check50 (5 times so far) but no longer runs from the command line. For example:

sfbob@ide50:~/workspace/pset2 $ ./caesar
Please enter a positive integer
sfbob@ide50:~/workspace/pset2 $ 4
bash: 4: command not found

I've run update50 twice this hour. What type of error should I look for:

Thank you.

Answer 1

Have you tried ./caesar 4?

When you have command-line arguments, you have to enter them all at once (i.e. on the same line), not one after the other.