What do you do to fix this string manipulation "match" returning nil?
Here's my script:
Players.PlayerAdded:Connect(function(plr)
plr.Chatted:Connect(function(msg)
-- Check for admin here.
if(msg:sub(1,1)=="/")then
local command, arg1, arg2 = msg:match("^%/(%S+)%s+(%a+)%s(.+)$")
print(command)
print(arg1)
print(arg2)
end
end)
end)
Everything's fine, I define the service Players elsewhere but if I added it this would be a standalone script.
The area of problem is here:
local command, arg1, arg2 = msg:match("^(%S+)%s+(%a+)%s(.+)$")
And it works like I want it to. Examples:
"/displayMessage all Hey guys!" print(command) -- displayMessage print(arg1) -- all print(arg2) -- Hey guys!
However some commands will only require two arguments, but then everything's nil.
"/kill me" print(command) -- nil print(arg1) -- nil print(arg2) -- nil
How could I fix this?
This code is mostly from one of my past questions.
I modified Blue's solution a little to fit my new situation here, but I'm still really bad with string manipulation. :c
Thanks for any help!
1 answer
With string.match nil will be returned if there is no capture found / matched.
For an admin script it might be best to build a argument table as this will support a ever changing amount or args ie one function to manage them all.
I find that it can simplify an admin script to just check for the admin command prefix in your case the / then cut out the prefix.
-- we should also check the string size before
if msg:sub(1,1) == '/' then
msg = msg:sub(2) -- remove the prefix
end
Now that we no longer have the prefix we can split the string using the white space followed by a varying number of characters ie [o or more white space characters] [as many non white space characters as possible]
We can represent this as a string pattern like so %S-(%a+).
But this will not capture any players with any numbers or commands with punctuation in so we need a set resulting in our finished pattern %S-([%a%d%p]+)
Example:-
local testData = {
'/kill me ??',
'/ kill me ??',
'/kill me',
'/ kill me',
'/kill',
'/ kill ',
'adsa',
'/displayMessage all Hey guys!',
'a',
'/kill guest11',
'/kill me!!'
}
for i=1, #testData do
print('--------- Test ' .. tostring(i) .. ' -----------')
local msg = testData[i]
if msg:sub(1,1) == '/' then
msg = msg:sub(2)
for c in msg:gmatch('%S-([%a%d%p]+)') do
print(c, #c)
end
end
end
Output:-
--[[ --------- Test 1 ----------- kill 4 me 2 ?? 2 --------- Test 2 ----------- kill 4 me 2 ?? 2 --------- Test 3 ----------- kill 4 me 2 --------- Test 4 ----------- kill 4 me 2 --------- Test 5 ----------- kill 4 --------- Test 6 ----------- kill 4 --------- Test 7 ----------- --------- Test 8 ----------- displayMessage 14 all 3 Hey 3 guys! 5 --------- Test 9 ----------- --------- Test 10 ----------- kill 4 guest11 7 --------- Test 11 ----------- kill 4 me!! 4 ]]
I hope this helps
