SubCoder

#!/bin/bash
# Author: MichalM.Mac

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Config

export ENCODING_FROM='CP1250'
export ENCODING_TO='UTF-8'
SUB_EXTENSION='.srt'

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

error_printer() {
  echo "$@" 1>&2;
}

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

convert_sub_encoding(){
  if file --mime-encoding "$1"  | grep -iq "$ENCODING_TO"; then
    error_printer "Error: File $1 is alredy encoded in $ENCODING_TO"
    return
  fi

  mv "$1" "${1}_temp"
  iconv -f "$ENCODING_FROM" -t "$ENCODING_TO" "${1}_temp" > "$1" && rm "${1}_temp"
}

find_subs(){
  export -f error_printer
  export -f convert_sub_encoding
  find "$1" -name "*${SUB_EXTENSION}" -exec bash -c 'convert_sub_encoding "$0"' {} \;
}

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Main Body

if [ $# -eq 0 ]; then
  echo "Error: No Aruments specified -> Nothing to do."
fi

# Postupné zpracování všech dodaných parametrů
while [ $# -gt 0 ]
do
  if [ -d "$1" ]; then
    find_subs "$1"
  elif [ -f "$1" ]; then
    convert_sub_encoding "$1"
  else
    error_printer "Error: $1 is not valid file or directory"
  fi

  shift
done