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[Solved] Catch error, display custom error message

Started by LoganDark, 17 June 2016 - 11:50 PM

LoganDark #1

LoganDark's profile picture

239 posts

Location Macintosh HD/Users/LoganDark

Posted 18 June 2016 - 01:50 AM

I want to use shell.run to run a program that may not exist, and I have my own error message that I want to display instead of "No such program". Is that possible?

Edited on 18 June 2016 - 12:00 AM

theoriginalbit #2

7508 posts

Location Australia

Posted 18 June 2016 - 01:55 AM

Error handling and Exceptions over at the Lua manual will point you in the direction of pcall.

It would go a little like this


local ok, err = pcall(function() shell.run("program") end)

if not ok then
  print("No program")
end

Edited on 17 June 2016 - 11:55 PM

LoganDark #3

LoganDark's profile picture

239 posts

Location Macintosh HD/Users/LoganDark

Posted 18 June 2016 - 01:56 AM

theoriginalbit, on 18 June 2016 - 01:55 AM said:
Error handling and Exceptions over at the Lua manual will point you in the direction of pcall.

It would go a little like this
local ok, err = pcall(function() shell.run("program") end)

if not ok then
  print("No program")
end

Okay, thanks. I forgot about pcall.

Bomb Bloke #4

Bomb Bloke's profile picture

7083 posts

Location Tasmania (AU)

Posted 18 June 2016 - 02:16 AM

shell.run() doesn't actually error if the targeted file doesn't exist. You'd be better off using fs.exists() to check before attempting to run in the first place.

LoganDark #5

LoganDark's profile picture

239 posts

Location Macintosh HD/Users/LoganDark

Posted 18 June 2016 - 02:18 AM

Bomb Bloke, on 18 June 2016 - 02:16 AM said:
shell.run() doesn't actually error if the targeted file doesn't exist. You'd be better off using fs.exists() to check before attempting to run in the first place.

Oh, okay.

Edit: So fs.combine shell.dir() and what to run?

Edit 2: I guess that's a yes

Edited on 18 June 2016 - 12:25 AM