View difference between Paste ID: QPBERWQY and eJtW9VDG

 function isUTF8ExtensionChar(char) {
     return (char >= "\200" && char < "\277")
 }
 
 # Extract a substring from a UTF-8 encoded string. This is required
 # since not all versions of awk respect the encoding specified by
 # $LANG. Of particular interest for me is the default busybox awk
 # within Alpine linux.
 function substrUTF8(str, start, len, inLen, subLen, inIndex, subIndex, outLen) {
     # Length of input string
     inLen = length(str)
 
     # Current index into input string
     inIndex = 1
 
     # Skip the initial unicode characters to get to starting index
     while (subIndex < start && inIndex <= inLen) {
         if (!isUTF8ExtensionChar(substr(str, inIndex, 1))) {
             inIndex++
             subIndex++
             while (isUTF8ExtensionChar(substr(str, inIndex, 1))) {
                 inIndex++
             }
         }
     }
 
     # Length of substring of input string which will produce the
     # output string
     subLen = 0
 
     # Starting index of input string which corresponds to the first
     # character of the output string
     subIndex = 1
 
     # Number of true unicode characters counted for output string
     outLen = 0
 
     # Calculate the end point of the sub string
     while (outLen < len && inIndex <= inLen) {
         if (!isUTF8ExtensionChar(substr(str, inIndex, 1))) {
             inIndex++
             subLen++
             outLen++
             while (isUTF8ExtensionChar(substr(str, inIndex, 1))) {
                 inIndex++
                 subLen++
             }
         }
     }
 
     return substr(str, subIndex, subLen);
 }