How to avoid blank input?

Hi everyone,
I need your help…

I have this code

data = read()
if data == "" then
error
elseif fs.exists(data) then
stuff
else
error
end

How can I check if data is composed by a lot of spaces?
If data is " " then fs,exists() will not give any error messages and the code will crash below

Thanks you!

You might want to look at Lua patterns. %s can be used to represent any whitespace character and conversely %S can be used to represent any non-whitespace character. You can then use string.find to see if there is a non-whitespace character:

if data:find("%S") then
  print(data)
else
  error("Just whitespace")
end

With fs.getSize(string path), can you check the Size of the file.

SquidDev, on 21 February 2016 - 02:45 PM said:

You might want to look at Lua patterns. %s can be used to represent any whitespace character and conversely %S can be used to represent any non-whitespace character. You can then use string.find to see if there is a non-whitespace character:

if data:find("%S") then
  print(data)
else
  error("Just whitespace")
end

Thanks you a lot!

SquidDev, on 21 February 2016 - 02:45 PM said:

You might want to look at Lua patterns. %s can be used to represent any whitespace character and conversely %S can be used to represent any non-whitespace character. You can then use string.find to see if there is a non-whitespace character:

if data:find("%S") then
  print(data)
else
  error("Just whitespace")
end

I think "not find".

if not data:find("%S") then
  print(data)
else
  error("Just whitespace")
end

Sewbacca, on 21 February 2016 - 03:00 PM said:

if not data:find("%S") then
  print(data)
else
  error("Just whitespace")
end

I think you're confusing %S with %s.

KingofGamesYami, on 21 February 2016 - 04:05 PM said:

I think you're confusing %S with %s.

Oh :blink:/>