Question

I’m currently just starting my first Lua program and I have a .csv file to read in. I want to check if the file I’m reading in is truely a .csv file.

I’ve tried regex similiar to these but they just don’t work..

s = string.match(arg[1], "%A+\.csv$")

whats the correct way to do the regex in lua?

Answer 1

In Lua patterns, you escape the meaning of a special character by using %, not \. Also, %A means a non-letter; a letter is %a (lowercase). So you seem to want one of these:

"^%a+%.csv$"             <-- one or more letters, plus ".csv"
"^%a.*%.csv$"            <-- a letter, plus zero or more characters, plus ".csv"