How can I verify that a file exists

Aitor

I'm trying something like this but it doesn't work

if { exists(0:/sys/config.g) }
	M291 R "EXISTS?" P "YES"
else
	M291 R "EXISTS?" P "NO"

How can I do it?

Best regards and thanks

dc42

@aitor testing whether a file exists is not currently supported. What is your use case?

Aitor

Good morning @dc42,

I want to check if the resurrect.g file exists when starting the machine, to be able to set the temperature of the base, because sometimes I have not been able to recover the piece because it had come unstuck.

And I'm sure I can think of more applications later

Thanks

OwenD

@aitor
You can fudge it with M38 "filename"
It will put an error message in the console if the file doesn't exist, but outside that it's workable.

M38 "some file"
if result != 0
	M291 P"File doesn't exist!" R"Houston we have a problem" S0 T3
else
	M291 P"File exists."  R"Life is good" S0 T3

Aitor

Thank you very much @owend for your input

It works fine, this is what I added in my config.g (is it the right place? where should I add it?)

M38 "0:/sys/resurrect.g"
if result != 0
	M291 P "No file" R "resurrect.g does not exist" S0 T3
else
	M916

But I would like to add one "if" more to avoid some problem that I have encountered, there is an object model that is "Last reset cause: power up" I can't find it if it exists.

On the other hand, to achieve the same thing without getting an error, there would be a way to write in a file like this:

M28 "0:/sys/runonce.g"
M916
M29

I have tried adding it to the M911 command in these two ways:

M911 S22 R23 P "M913 X0 Y0 Z0 E0 M28 "0:/sys/runonce.g" M916 M29"

Adding the quotes to M28 closes M911 and does not work.

M911 S22 R23 P "M913 X0 Y0 Z0 E0 M28 0:/sys/runonce.g M916 M29"

Removing the quotes works but it takes it as a name (runonce.g M916 M29) and does not write anything inside.

Do you know any way to avoid this?

Best regards and thanks again

OwenD

@aitor
To be honest I'm not sure if automated restarting after a failure is a smart move.
There are lots of things that could go wrong if there's a power outage during a print.

Also my code isn't quite accurate
The result of the file doesn't exist would be 2
M38 could fail for other reasons and return code 1
So use

iM38 "some file"
if result == 2
   echo "file doesn't exist

Have you read this?
https://duet3d.dozuki.com/Wiki/Setting_up_to_resume_a_print_after_a_power_failure

Aitor

Good morning @owend,

You are right doing an automatic recovery is dangerous that's why my resurrect-prologue.g contains:

var temp = heat.heaters[1].active

M116 ; wait for temperatures
G28 XY ; house X and Y, I hope Z hasn't moved
G10 P0 S0
M291 R "Recovery" P "Want to recover the part" S2 T0
G10 P0 S{var.temp}
M116 P0

so I just keep the bed heater on until I get there.

if I recovery the part and ends, resurrect.g it will be deleted.

if it turns out that I don't want to recovery the part, I have added to cancel.g the following:

if global.delete = 1
	M471 S"/sys/resurrect.g" T{"/sys/resurrect1.g"} D1
	set global.delete = 0

this is what I've added in my config.g (then I'll try the last thing you indicated)

global delete = 0
M38 "0:/sys/resurrect.g"
if result != 0
	don't do anything
else
	set global.delete = 1
	M916

I really wanted to use the M291 command in my resurrect-prologue.g as S3, "ok " to continue and "cancel" to not continue, but I have not been able to, so I have had to do this less nice alternative for now.

Thanks for the help, it is being very useful and I am learning a lot.

dc42

@aitor said in How can I verify that a file exists:

Adding the quotes to M28 closes M911 and does not work.

Use two double-quote characters inside a string literal:

M911 S22 R23 P "M913 X0 Y0 Z0 E0 M28 ""0:/sys/runonce.g"" M916 M29"

oozeBot

@aitor said in How can I verify that a file exists:

I really wanted to use the M291 command in my resurrect-prologue.g as S3, "ok " to continue and "cancel" to not continue, but I have not been able to, so I have had to do this less nice alternative for now.

Maybe this will help?

https://forum.duet3d.com/topic/23423/m291-solution-to-handling-both-ok-cancel

Aitor

Good morning @dc42

This did not work:

M911 S22 R23 P "M913 X0 Y0 Z0 E0 M28" "0: /sys/runonce.g" "M916 M29"
Error: M911: expected string expression

Good morning @oozebot

I've been trying it , very useful, but it didn't work for me or I didn't know how to make it work in my application, because I can exit the macro where I have the message (i.e. resurrect-prolonge.g) but I'm still in resurrect.g so no matter what I answer it keeps going.

For other applications it is a marvel that I am already implementing.

It would be nice to have a M291 S4 YES or NO that would assign TRUE or FALSE to an already defined global variable or something like that

Thanks again to all

Phaedrux

@aitor said in How can I verify that a file exists:

This did not work:

Try without the spaces between the quotes.

dc42

@aitor said in How can I verify that a file exists:

This did not work:
M911 S22 R23 P "M913 X0 Y0 Z0 E0 M28" "0: /sys/runonce.g" "M916 M29"
Error: M911: expected string expression

Do not put space characters between the two double quote characters.

Aitor

Good morning @phaedrux @dc42 @owend @oozebot

When I deleted the double quotes it didn't give me an error, but it generated a blank file, I realised it was because I was trying to run M916 but it didn't exist yet, so I solved it this way.

M911 S22 R23 P "M913 X0 Y0 Z0 E0 M28""0:/sys/runonce.g"" M98 P""run1.g"" M29"

in run1.g I typed M916 and this did work as expected

only that runonce.g is not deleted, something that is good for me because I thought that if I had two blackouts in a row without having recovered this would be deleted and would not work as I wanted, when I finish printing is not deleted either, only to restart again, this makes some errors appear, so I added to my final script and my cancel.g a M30 to delete it.

This was my solution and it works fine so far:

config.g I added:

M911 S22 R23 P "M913 X0 Y0 Z0 E0 M28""0:/sys/runonce.g"" M98 P""run1.g"" M29"
; Global Variables
global delete = 0

run1.g contains:

set global.delete = 1
M916

resurrect-prologue.g contains:

var temp = heat.heaters[1].active

M116 ; wait for temperatures
G28 XY ; house X and Y, hope Z hasn't moved
G10 P0 S0
M291 R "Recovery" P "Want to recover the part" S2 T0
G10 P0 S{var.temp}
M116 P0

final script I added: (resurrect.g if automatically deleted)

if global.delete = 1
	M30 "/sys/runonce.g"
	set global.delete = 0

cancel.g I added:

if global.delete = 1
	M471 S"/sys/resurrect.g" T{"/sys/resurrect1.g"} D1 ; I rename it in case I want to use it later on.
	M30 "/sys/runonce.g"
	set global.delete = 0

I hope you find this solution useful and if you think of any improvement I will be happy to hear it.

Best regards and thanks for your support.