Linux结构化语句-判断

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# 数值判断
if [ 1 -eq 1 ]
then
  echo  "Welcome to Biotrainee() !"
else
  echo  "**************"
fi

# 结合状态参数 $?
if [ $? -eq 0 ]
then
  touch  ok.txt
fi

# 文件判断
if [ ! -f ok.txt ]
then
  touch  ok.txt
fi