Tcl

Convert a File's Character Encoding from UTF-8 to UFT-8-BOM

See more HTML-to-XML/Text Examples

To add a utf-8 BOM to a file is just a matter of prepending these 3 bytes to the file: 0xEF 0xBB 0xBF.

This may be difficult in some programming languages, or it may be trivial in either. Therefore, the Chilkat solution you see here might be helpful, or in a language such as C++, the Chilkat solution isn't really necessary because it's easy to do yourself.

Tcl

load ./chilkat.dll

set success 0

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

set charset [new_CkCharset]

CkCharset_put_FromCharset $charset "utf-8"
CkCharset_put_ToCharset $charset "bom-utf-8"

set success [CkCharset_ConvertFile $charset "qa_data/txt/helloWorld.txt" "qa_output/helloWorldBom.txt"]
if {$success != 1} then {
    puts [CkCharset_lastErrorText $charset]
    delete_CkCharset $charset
    exit
}

puts "Success."

delete_CkCharset $charset