merge utf-8 BOM csv files into single file and keep header from first file.

merge_bom.sh

#!/bin/bash
# ref:https://zzz.buzz/2016/07/30/bom-in-iconv/
# ref:https://stackoverflow.com/questions/16890582/unixmerge-multiple-csv-files-with-same-header-by-keeping-the-header-of-the-firs

for filename in *.csv; do
  sed -i 's/\xef\xbb\xbf//' $filename
done

awk 'FNR==1 && NR!=1{next;}{print}' *.csv > merge-bom.csv