Translate SRT file into another language using Google Translate

translate.sh

#!/bin/bash

# Requires translate-shell to be installed.
# Get it on GitHub at: https://github.com/soimort/translate-shell

# Parse command-line arguments
while [[ "$#" -gt 0 ]]; do
    case $1 in
        --file|-f ) file="$2"; shift ;;
        --language|-l ) language="$2"; shift ;;
        * ) echo "Unknown option: $1"; exit 1 ;;
    esac
    shift
done

# Check that required arguments are provided
if [[ -z "$file" ]]; then
    echo "Error: Input file not specified."
    echo "Usage: $0 --file <input_file> --language <language_code>"
    exit 1
fi

if [[ -z "$language" ]]; then
    echo "Error: Language code not specified."
    echo "Usage: $0 --file <input_file> --language <language_code>"
    exit 1
fi

if [[ ! -f "$file" ]]; then
    echo "Error: Input file '$file' does not exist or is not a regular file."
    exit 1
fi

if ! [[ $language =~ ^[a-z]{2}$ ]]; then
    echo "Error: Language code '$language' is not valid. Please use a two-letter language code (ISO 639-1)."
    exit 1
fi

# Read input file and translate if necessary
while read -r line; do
    if [[ "$line" =~ [a-z] ]] ; then
        translated=$(echo "$line" | trans -brief ":$language")

        if [[ $? -ne 0 ]]; then
            echo "Error: Translation failed for '$line'. Skipping."
        else
            echo "$translated" >> "${file%.*}.$language.srt"
        fi
    else
        echo "$line" >> "${file%.*}.$language.srt"
    fi
done < "$file"