--[[
io.read (by default) reads from the keyboard

Basic string functions all all in the string MODULE (table)
]]

print ("say something... ")
what = io.read()
print ("You said -> " .. what)

print ("\nNumeric conversion and testing")
numval = tonumber(what)
if numval == nil then
        print ("That is not a number")
else
        print ("doubles to " .. numval * 2)
end

print ("\nString Conversions")
print (string.lower(what))
print (string.upper(what))
print (string.reverse(what))
print (string.rep(what,4))

print ("\nwithin and part strings")
size = string.len(what) -- same as the # operator
print (string.sub(what,1,size/2))
print (string.sub(what,size/2,-1)) -- count down from end
print (string.byte(what,1,#what))
bytes = {string.byte(what,1,#what)} -- ick! returns multivals not a table

remake = ""
for k=1,#bytes do
        if bytes[k] > 96 then
                bytes[k] = bytes[k] - 32
        elseif bytes[k] > 64 then
                bytes[k] = bytes[k] + 32
        end
        remake = remake .. string.char(bytes[k])
end

print (remake) -- Swap Case

--[[ --------------------- Sample Output
[trainee@easterton u104]$ lua gimme
say something...
Lua Training!
You said -> Lua Training!

Numeric conversion and testing
That is not a number

String Conversions
lua training!
LUA TRAINING!
!gniniarT auL
Lua Training!Lua Training!Lua Training!Lua Training!

within and part strings
Lua Tr
raining!
76 117 97 32 84 114 97 105 110 105 110 103 33
lUA tRAINING!
[trainee@easterton u104]$

[trainee@easterton u104]$
]]