Couple big things are 1. Only accept reasonable characters, on a white list instead of rejecting bad characters based on a black list. This will mean you are less likely to forget to block /0 for example. 2. Understand how strings work and ensure both reading and writing to that string doesn't extend beyond the end of memory allocated for the string. For example do you understand what the /0 would do to a string your program accepts?

[–] akunohana@piefed.blahaj.zone 5 points 3 hours ago (1 children)

Sic! Thanks! I'll work on this this weekend! 😊

[–] vrek@programming.dev 6 points 3 hours ago

Keep in mind, the lowercase and uppercase letters are in continuous blocks on the ASCII table so you can can use that to verify if a char is a letter without doing an incredible long chain of if else statements.