Change the charset of a file

changechset.sh

#!/usr/bin/env bash

set -Eeuo pipefail
trap cleanup SIGINT SIGTERM ERR EXIT

script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" &>/dev/null && pwd -P)

usage() {
  cat <<EOF
Usage: $(basename "${BASH_SOURCE[0]}") [-h] [-v] [-f] -i INPUT_FILE -e OUTPUT_CHARSET -o OUTPUT_FILE

Given an INPUT_FILE, create an OUTPUT_FILE with charset OUTPUT_CHARSET.

Example: $(basename "${BASH_SOURCE[0]}") -i test.sql -e utf-8 -o out.sql

Available options:

-h, --help       Print this help and exit
-v, --verbose    Print script debug info
-s, --silent     Silent mode
-i, --input      Input file
-e, --output-chs Charset used in output file
-o, --output     Output file
EOF
    exit
}

cleanup() {
    trap - SIGINT SIGTERM ERR EXIT
    # script cleanup here
}

setup_colors() {
    if [[ -t 2 ]] && [[ -z "${NO_COLOR-}" ]] && [[ "${TERM-}" != "dumb" ]]; then
        NOFORMAT='\033[0m' RED='\033[0;31m' GREEN='\033[0;32m' ORANGE='\033[0;33m' BLUE='\033[0;34m' PURPLE='\033[0;35m' CYAN='\033[0;36m' YELLOW='\033[1;33m'
    else
        NOFORMAT='' RED='' GREEN='' ORANGE='' BLUE='' PURPLE='' CYAN='' YELLOW=''
    fi
}

msg() {
    if [ $silent == 0 ]; then
        echo >&2 -e "${1-}"
    fi
}

step(){
    msg "${BLUE}${1-}...${NOFORMAT}"
}

die() {
    local msg=$1
    local code=${2-1} # default exit status 1
    msg "${RED}$msg"
    exit "$code"
}

parse_params() {
    # default values of variables set from params
    input=''
    output_chs=''
    output=''
    silent=0

    while :; do
        case "${1-}" in
            -h | --help) usage ;;
            -v | --verbose) set -x ;;
            --no-color) NO_COLOR=1 ;;
            -s | --silent) silent=1 ;;
            -i | --input) input=${2-}  && shift;;
            -e | --output-chs) output_chs=${2-}  && shift;;
            -o | --output) output=${2-}  && shift;;
            -?*) die "Unknown option: ${1-}" ;;
            *) break ;;
        esac
        shift
    done

    args=("$@")

    # check required params and arguments
    [[ -z "${input}" ]] && die "Missing required parameter: input"
    [[ -z "${output_chs}" ]] && die "Missing required parameter: output-chs"
    [[ -z "${output}" ]] && die "Missing required parameter: output"

    return 0
}

setup_colors
parse_params "$@"

# script logic here

if [ -f "$input" ]; then
    msg "${BLUE}$input exists."
else
    die "$input does not exist."
fi

step "Reading parameters"
msg "- input: ${input}"
msg "- output-chs: ${output_chs}"
msg "- output: ${output}"

step "Checking input charset"

file_info=`file -i ${input}`
charset_in=''

if [[ $file_info =~ .+charset=(.+) ]]; then
    charset_in=${BASH_REMATCH[1]}
    msg "charset=${charset_in}"
else
    die "Cannot define charset of ${input}. Result ${file_info}"
fi

step "Creating output file"

if [ $charset_in == $output_chs ]; then
    msg "The charset of input is equal to charset of output."
    exit 0
fi

iconv -f $charset_in -t $output_chs "$input" -o "$output" && msg "Done!" || die "Bad use of iconv."