Wait a file exist

[papiosaur]

Hello,

i would like realize an action on a file but i must wait it exist before realize the action.

Is there a possibility to do a loop about that?

Thanks a lot for your help!

[Flinx]

You have two options. A loop is simple.

Code: Select all

filename$="test.txt"
Repeat
	Cls
	If Exists(filename$)
		TextOut(#CENTER, #CENTER, filename$.." exists")
	Else
		TextOut(#CENTER, #CENTER, filename$.." does not exist")
	EndIf
	Wait(100,#MILLISECONDS)
Forever

But a loop always requires computing time. An event would be the smarter solution.
In the following example the current directory is monitored (".").

Code: Select all

filename$="test.txt"
Function p_EventDirectoryChanged(msg)
	Cls
	TextOut(#CENTER, #CENTER, "id: "..ToString(msg.id).."\ndirectory: "..msg.directory.."\naction: "..msg.action.."\ntype: "..msg.type.."\nname: "..msg.name)
EndFunction

InstallEventHandler({DirectoryChanged=p_EventDirectoryChanged})
MonitorDirectory(1, ".",{ReportChanges=True})

Repeat
	WaitEvent()
Forever

[jPV]

Unfortunately ReportChanges=True for the MonitorDirectory() does only work on Windows and OS4, AFAIK. At least it fails on MorphOS, which papiosaur uses I guess.

Here are my two more options

If doing purely with Hollywood and don't want to use the looping solution, something like this with the MonitorDirectory() (a bit clumsy example and would need finetuning depending on the final goal):

Code: Select all

Function p_Monitor(msg)
    If Exists(msg.MonitorUserData)
        Print("The file is here!")
        ; Do something with the file

        ; And then stop monitoring
        CloseDirectory(g_monitorid)
        g_monitorid = Nil
    EndIf
EndFunction

Function p_MonitorFile(file$)
    Local dir$  = PathPart(file$)
    MakeDirectory(dir$)
    InstallEventHandler({DirectoryChanged = p_Monitor})
    g_monitorid = MonitorDirectory(Nil, dir$, {UserData=file$})
EndFunction

p_MonitorFile("Ram Disk:test/testfile")

Repeat
    WaitEvent
Forever 

Or if you are creating a program for MorphOS only and want to block the script execution while waiting a file to appear, you can use the WaitForNotification shell command.

Code: Select all

file$ = "Ram Disk:test/testfile"
If Not Exists(file$)
    Execute("WaitForNotification", "\"" .. file$ .. "\"")
EndIf

[papiosaur]

Thanks lot guys !!!

I will try them.

[papiosaur]

I use WaitForNotification command on MorphOS and it work but i will try the others solutions to understand better

What i must do when i use FileToString() command, how to know when the conversion is finalized please?

Thanks!

[jPV]

What i must do when i use FileToString() command, how to know when the conversion is finalized please?

No need to do anything, the script halts until a file is read in a string and continues to the next command when it's done.

[papiosaur]

@jPV: Sometimes the conversion is too long and the string is not showed in a log window asked just after.

Note: i compile a c source file with gcc via the GUI and after i want to execute the exe too

I would like to show the outfile in a log window and i must use FileToString() command to do that.

I use Wait() command but i don't like this solution.

[papiosaur]

Ok, seems ok now, i realize the test of the outputfile before FileToString() command