Script line Error Tracking

[NICKI004]

I have several automated processes that run 24/7. I do have several error handling scripts in place to handle issues I know may occur. However, there are times that Alpha will have it's own problem and I have no idea where in my script the error occurred. It takes me a lot of time, sometimes in the middle of the night, to figure out where I need to "start" the code up again to complete the script run.

Is there anything that Alpha has that I am unaware of, or does anyone have any ideas, on how to know what line exactly a script errored out on? The error doesn't always specify and can be very vague as in: Error running Append Operation. Well I have about 20 append operations that are called in that script so which one did it fail on?

I have thought of some different solutions but they are inefficent. For example, I thought about having a little table and I would update the line # field EVERY TIME I pass I line of code. This would slow my program down and is very ineffiecent. I also thought of just writing to a text file wtih teh line number, as this is somewhat faster. However, if the program fails, the text file doesn't get closed and I think the last few or so lines wouldn't get saved into it?? I am out of ideas and thought I better check on here before I re-invent a wheel that may already be out there

Thank you, Nicki

[Keith Hubert]

Re: Script line Error Tracking

Hi Nicki,

The best way to see if an operation has failed is not to run it in Silent mode.

If all your code is in Xbasic then use Debug(1) and then you can test the values as the script progresses.

Also, consider writing to the Trace Window.

[Stan Mathews]

Re: Script line Error Tracking

Following other's advice I have converted operation scripts to functions like...

FUNCTION add_to_wss AS L ( )
	add_to_wss = .F.
	'This script adds any newly sold items in a week.
	DIM Append as P
	'open in exclusive mode if available
	filitm = a5.Get_Path()+chr(92)+"wss.DBF"
	itmtest = table.in_use(filitm)
	IF itmtest
		a_tbl = table.OPEN(a5.Get_Path()+chr(92)+"wss.DBF")
	ELSE
		a_tbl = table.OPEN(a5.Get_Path()+chr(92)+"wss.DBF",FILE_RW_EXCLUSIVE)
	END IF
	'append any new items from the temporary sales import file to the weekly sales history file
	append.t_db = "ws01ttl"
	append.m_key = "Upc-Store"
	append.t_key = "F01-F1056"
	append.m_filter = ""
	append.t_filter = "Total_F65<>0"
	append.type = "Unique only"
	append.m_count = 3
	append.m_field1 = "UPC"
	append.m_exp1 = "@WS01TTL->F01"
	append.m_field2 = "STORE"
	append.m_exp2 = "@WS01TTL->F1056"
	append.m_field3 = "DEPT"
	append.m_exp3 = "@WS01TTL->First_F04"
	append.t_count = 0
	a_tbl.append()
	a_tbl.close()
	add_to_wss = .T.
         op_write("add_to_wss","Maintenance")
	END FUNCTION

The op_write() function is

FUNCTION op_write AS L (operation AS C, origin as C )
	op_tbl = table.open("op_trace",FILE_RW_EXCLUSIVE)
	op_tbl.enter_begin()
	op_tbl.Op = operation
	op_tbl.Date_op = time("mon dd, yyyy 0h:0m  am",now())
	op_tbl.Origin = origin
	op_tbl.enter_end(.t.)
	op_tbl.close()
	op_write = .t.
END FUNCTION

The op_trace table has the structure.

Op	Character	50	0	
Date_Op	Character	22	0	
Origin	Character	50	0

So if the function add_to_wss completes I know it did and when.

[NICKI004]

Re: Script line Error Tracking

Thanks, this is kind of along the same idea I had about updating a table. I guess I was hope maybe Alpha had a log file or tracer or something that kept track of what lines were processed in a script. Thanks!

[Stan Mathews]

Re: Script line Error Tracking

There is a log/tracer function PROFILER_BEGIN() but for it to perform the corresponding PROFILER_END() must be issued. If the script fails you wouldn't get the output.

[NICKI004]

Re: Script line Error Tracking

And the thing is, my code all works fine for a month and then one script will randomly fail. Once I find where it failed, I can copy from there down into a blank script, run it and move on fine so it's not a problem in my code. My issue here is trying ti find the exact line it failed so I know where to start my copy from to run.

[Purvi]

Re: Script line Error Tracking

Thanks, this is kind of along the same idea I had about updating a table. I guess I was hope maybe Alpha had a log file or tracer or something that kept track of what lines were processed in a script. Thanks!

Nicki, I was wondering if you got the answer to this Question? Does Alpha have a Generic Error Log that keeps track of what lines were processed in scripts that ran in one session? I.e. Error Logging functionality in .NET.

[Tom Henkel]

Re: Script line Error Tracking

Something else you might want to do is to put "restart" labels into your code and then at the beginning, test for where to restart and just "jump" (goto) that location.

Tom

[Mike Wilson]

Re: Script line Error Tracking

Stan's method appears to be an elegant method to log the course of successful processes. Nick I believe is looking to have the capability to identify the point of failure (or error). For very complicated scripts, I have begun to add a char variable err_trk and err_trk_scr = <current script name> and place it in the script at various lines throughout out the script where certain actions are occurring and updating the variable with err_trk = err_trk_scr + " start <Action> @ line # <line#>". Then at the start of the script I place an "on error goto error_handler" and have that value of the err_trk variable written to a tracking table, similar to what Stan wrote. It's kind of crude, but has worked very well so far to immediately identify the region of a script where failure has happened.

[CALocklin]

Re: Script line Error Tracking

For very complicated scripts, I have begun to add a char variable err_trk ....

I like it!

[Stan Mathews]

Re: Script line Error Tracking

My thought was to use

on error goto err_hndlr
PROFILER_BEGIN()

at the start of the script and then

profiler_end()
end
err_hndlr:
profiler_end()

at the end.

[aschone]

Re: Script line Error Tracking

I have this code in every script and UDF that I have written. In the event of an error a message box is displayed that shows error #, error text, name of the script that generated the error and the line number of the script where the error was encountered. Output of the error info can be changed to write to a log file, table, trace window, or any other place you desire.

If you are running an operation this will help you track down which operation tripped the error.

OPTION STRICT
OPTION ENCRYPTED_TOKENS
ON ERROR GOTO ERR_HANDLER



END
'-----------------------------------
'Error handler
'-----------------------------------
ERR_HANDLER:
	DIM vErrN as N 
	DIM vMsgC as C
	vErrN = error_code_get()

	vMsgC = "Error # "+ vErrN + crlf() + error_text_get(vErrN)
	vMsgC = vMsgC + crlf() + "Script: " + error_script_get()
	vMsgC = vMsgC + crlf() + "Line #: " + error_line_number_get()

	trace.writeln(vMsgC)

	ui_msg_box("Error", vMsgC,UI_ATTENTION_SYMBOL)
	vMsgC = ""
	
	END

[CALocklin]

Re: Script line Error Tracking

I have this code in every script and UDF that I have written. In the event of an error a message box is displayed that shows error #, error text, name of the script that generated the error and the line number of the script where the error was encountered. Output of the error info can be changed to write to a log file, table, trace window, or any other place you desire.

If you are running an operation this will help you track down which operation tripped the error.

My generic error handler also uses the error_line_number_get(), etc. but I've found that the error handler doesn't get tripped by certain errors. I think that's generally errors that occur in some standard A5 "operation" (could be an official Operation saved in the Operations tab or something else - not sure) that runs "outside" of my script. In those cases, some other form of line tracking may be required.

[aschone]

Re: Script line Error Tracking

My generic error handler also uses the error_line_number_get(), etc. but I've found that the error handler doesn't get tripped by certain errors. I think that's generally errors that occur in some standard A5 "operation" (could be an official Operation saved in the Operations tab or something else - not sure) that runs "outside" of my script. In those cases, some other form of line tracking may be required.

This is true, I have found operations called via %operation%.run() or %operation%.run_silent() will not trip the error catch routine in the script. Same will happen if calling a public UDF. Due to this I will convert the operation to xbasic code as discussed by Stan in post #3. For the public UDF I will also include the same error catch routine to trap those errors.