File written to disk truncated to multiples of 4096 chars

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kaveh1000
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File written to disk truncated to multiples of 4096 chars

Post by kaveh1000 » Tue Dec 18, 2018 8:46 pm

I am writing some text to a file on disk using the standard procedure:

Code: Select all

open file my_file for text write
write fld "text" to file my_file
The file is getting truncated to specific numbers of characters and I notice the number of chars is a multiple of 4096, for instance:

4096
40960
61440


Any ideas pls?
Kaveh

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Re: File written to disk truncated to multiples of 4096 chars

Post by Klaus » Tue Dec 18, 2018 8:58 pm

Hi Kaveh,

does the shorter URL syntax work?

Code: Select all

...
put fld "text" into url("file:" & my_file)
...
?

Best

Klaus

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Re: File written to disk truncated to multiples of 4096 chars

Post by dunbarx » Tue Dec 18, 2018 9:11 pm

This works fine for me in v 8.1.10. The length of the text file is a bit over one Meg:

Code: Select all

on mouseUp
   put "aslkjfhlasflsakflsalfklsakfjlskflsjf" into temp
   repeat 15
      put temp after temp
   end repeat
   
   answer the length of temp
   
   put  "/users/craignewman/desktop/XXX" into filePath
   
     open file filePath for text write
   write temp to file filePath
   close file filePath
end mouseUp

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Re: File written to disk truncated to multiples of 4096 chars

Post by FourthWorld » Tue Dec 18, 2018 9:15 pm

Number of characters or number of bytes? How are you assessing that?

If assessment is from the file manager that's normal, as most OSes ship with a file system that uses a 4k block size by default.

That assumes, of course, that the number you're seeing is rounding up, rather than down, yes?
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kaveh1000
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Re: File written to disk truncated to multiples of 4096 chars

Post by kaveh1000 » Tue Dec 18, 2018 9:29 pm

@Klaus:

Your solution seems to work. Thank you. :-)

@Richard:

Number of chars, which is weird. I open in a text editor that shows no of chars. As I add characters to the top of the file, the same number are deleted from the bottom.

@Craig:

I am getting truncation even with very short text, e.g. truncated to 4096 chars.

Love to know the cause! Thank you to all as ever. :-)
Kaveh

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Re: File written to disk truncated to multiples of 4096 chars

Post by kaveh1000 » Tue Dec 18, 2018 9:32 pm

I have an "on idle" handler running while testing. I wonder if that could be the reason.
Kaveh

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Re: File written to disk truncated to multiples of 4096 chars

Post by ClipArtGuy » Tue Dec 18, 2018 9:36 pm

kaveh1000 wrote:
Tue Dec 18, 2018 9:32 pm
I have an "on idle" handler running while testing. I wonder if that could be the reason.
Can you use a "send in time" instead of idle? I can't remember where, but I was warned off of using idle unless absolutely necessary. Send in time works everywhere I've ever needed it.

There's this little bit from the livecode wiki:
Executing an idle handler slows down other LiveCode actions, so handle the idle message only in the rare cases where the send command cannot be used instead.

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Re: File written to disk truncated to multiples of 4096 chars

Post by FourthWorld » Tue Dec 18, 2018 10:00 pm

kaveh1000 wrote:
Tue Dec 18, 2018 9:32 pm
I have an "on idle" handler running while testing. I wonder if that could be the reason.
Depends on what it does. Please consider posting the simplest stack you can come up with which exhibits the problem.
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Re: File written to disk truncated to multiples of 4096 chars

Post by kaveh1000 » Tue Dec 18, 2018 10:26 pm

I'll try and make a minimal stack to post, Richard, but it is linked with some unfinished stuff that I can't post...

I can confirm it is not due to the idle handler. I have switched off and retested with same results.
Kaveh

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