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bw_bloodletter
Inspiring
January 7, 2021
Answered

Adding UTF-8 BOM (Byte Order Mark) To File Output

  • January 7, 2021
  • 1 reply
  • 2611 views

We're exporting some data to CSV files and when using CFFILE (write/append) with CHARSET set to "utf-8", the file seems to be properly encoded, but there's not BOM (byte order mark) at the beginning of the file.

 

As far as I know, this is standard practice as the BOM is optional.  Some applications (like Notepad) open the file just fine, and render the UTF-8 accented characters, angled quotations, etc. just fine.

 

Excel, however, has issues when opening the file if the BOM is not present.  If I manually add the BOM to the beginning of the file using another application, Excel opens it fine (and so does Notepad).

 

Is there a simple / recommended way to add the BOM to the file using CFFILE or other built-in functionality?

 

The BOM character entry in UTF-8 is U+FEFF (65279) or EF, BB, BF in raw hex.  So currently, I'm starting our file output with CHR(65279), and this does seem to work.

 

Thanks

    Correct answer bw_bloodletter

    From my previous post:

    So currently, I'm starting our file output with CHR(65279), and this does seem to work.

     

    I was just wondering if this is the "correct" way to do it, or if there was some other recommended way.

    1 reply

    BKBK
    Community Expert
    BKBKCommunity Expert
    Community Expert
    January 9, 2021

    You should try something like:

    <cfset OutputContent=chr(65279) & "abbcccdddd some arbitrary text content">

<cfset absolute_path_to_output_file="C:\Users\BKBK\Desktop\output.txt">

<cffile action = "write" file = "#absolute_path_to_output_file#" output = "#OutputContent#" charset="UTF-8">
    B
    bw_bloodletterAuthorCorrect answer
    Inspiring
    January 12, 2021

    From my previous post:

    So currently, I'm starting our file output with CHR(65279), and this does seem to work.

     

    I was just wondering if this is the "correct" way to do it, or if there was some other recommended way.

      BKBK
      Community Expert
      BKBKCommunity Expert
      Community Expert
      January 12, 2021

      Oh, I see. I wasn't so sure about what you meant, so focused on the ColdFusion question, "Is there a simple / recommended way to add the BOM to the file using CFFILE or other built-in functionality?". So, we both have the same idea. And that is the "correct" way as far as I know.

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