Recipe: version print

created by brgreening

Profile

• Name: version print
• ID: 47844
• Shared with: Public
• Parent: None
• Children: None
• Created on: January 23, 2014 at 03:58 AM UTC
• Updated on: January 23, 2014 at 03:58 AM UTC
• Description:

  this prints the Lua Version

Code

-- DO NOT RUN THIS SCRIPT
-- it is for demonstrating that a bad Lua script
-- can crash Foldit
-- It demonstrates that an invalid argument for os.date( "%Q" ) or
-- doing a divide by zero in a Lua script can crash Foldit
-- It crashes when using Lua 5.1.   This crashes for the current 1/22/2014 version of Foldit
-- Using Lua 5.2 in the Windows Lua compiler gets around this.
-- This bug is mentioned in https://fold.it/portal/node/996624

print( "Lua Version: ", _VERSION )

x_str = os.date( "%X" )
print( "Valid argument for Lua os.date() works ", x_str ) 

x1_val = 1.0
x2_val = 3.0

print( "Doing divide with non-zero divisor: ", x1_val / x2_val )


x2_val = 0.0

print( "Attempting divide with zero divisor: ", x1_val / x2_val )  -- **** this will crash Foldit ****


x_str = os.date( "%Q" )    -- **** this will crash Foldit *****

print( "Invalid argument for Lua os.date() ", x_str )

Comments

[brgreening]

This script is to demonstrate that an invalid argument to the os.date( "%Q" ) statement in a Lua script or attempting to divide by zero in a Lua script will crash Foldit. I was running Foldit under Windows 8. I would be interested in
what this script does in Linux or on a Mac.

Current Foldit uses Lua 5.1.

I downloaded Lua 5.2 and ran it using Windows Lua compiler. The errors seem to be handled better there. It prints out an error message rather than crashing.

[brgreening]

The software release,
20140811-46cd6bb2fb-win_x86-devprev,
Fixed these bugs.

Lua Version: Lua 5.1
Foldit run on this date: 08/11/14 15:29:58
Valid table index: 902
Invalid table index: nil
Valid argument for Lua os.date() works 15:29:58
Doing divide with non-zero divisor: 0.33333333333333
Attempting divide with zero divisor: 1.#INF
Invalid argument for Lua os.date() 15:29:58

http://fold.it/portal/recipe/47844

a recipe called “version print” has been created to test these functions

There is no indication as to where the error occurred. Lua is compiled into a series of function calls when executed. Something like “Divide by zero in function check_helix + 128 “ would be nice.