When I run vigenere I get the message
Segmentation fault (core dumped). I understand that this means that I am accessing memory that should not be accessed, but I do not see why or how. I begin with
argc = 2. I am trying to save the second string
argv as my key variable. Then I use
isalpha to determine if it is a letter. I error out of the program if it is not.
On a related note I tried to use gdb but it kept asking me for a file. Can I use the debugger for this type of problem?