zsh ./fuck.sh $1 $2 $3 ...

if [ "${message}"x = x ]
then
  echo "equal"
elif [ "${message}"x = "shitx" ] || [ "${message}"x = "SHIT" ]
then
  echo "shit"
else
  echo "fuck"
fi

for img in `ls`
do
  if [[ $img == _* ]]
  then
    output=${img#_}
    # echo ${output}
    ffmpeg -i ${img} -vf "scale=iw/5:ih/5" ${output} -y
  fi
done

line_num=$(wc -l $1)
echo ${line_num}
i=0
while [ ${line_num:${i}:1} != " " ]
do
  ((i++))# 寻找空格
done
line_num=${line_num:0:${i}}
echo ${line_num}
version=$(uname)
if [ "${version}" = "Linux" ]
then
  sed -i 's/\t/  /g' $1
  sed -i 's/  / /g' $1
elif [ "${version}" = "Darwin" ]
then
  sed -i '' 's/<C-v><tab>/  /g' $1 #这个地方指按下ctrl+v,然后再按一下tab,输出tab字符
  sed -i '' 's/  / /g' $1
fi

sed -i '' -e '4a\
'${message} ${filename}

sed -i '' -e '4a\
shit' ${filename}

sed -i '4a\shit' ${filename}

sed -i '4a\'${message} ${filename}

${#string}

sh=()
sh+=(1)
sh+=(2)
for i in $sh
do
  echo $i
done