老师布置的一道关于Linux的一道题求解主要是代码

用vim写个bash脚本，判断某个文件是否存在，如果存在，调用ffmpeg将文件夹下以FLAC1_ 开头的扩展名为.flac的文件转换为mp3格式

猜測應該是先判断某个文件**夾**是否存在，
script中ffmpeg的參數再自行調整

#!/bin/bash

FFMPEG_BIN="ffmpeg-4.0.1/ffmpeg"
MUSIC_PATH="music"

if [[ -d ${MUSIC_PATH} ]]; then
    echo "MUSIC_PATH exists."
    flac_files=`find ${MUSIC_PATH} -name "FLAC1_*.flac"`
    if [[ -z "${flac_files}" ]]; then
        echo "No flac files in directory ${MUSIC_PATH}"
        exit
    fi
    echo "Start to convert flac format to mp3 format"
    for input_file in ${flac_files}
    do
        output_file=${input_file/flac/mp3}
        echo -e "\n${input_file} ==> ${output_file}"
        ${FFMPEG_BIN} -i "$input_file" -ab 320k -map_metadata 0 "${output_file}"
    done
else
    echo "MUSIC_PATH doesn't exist."
fi