Shell one of the basic applications

  • 输出可执行文件的文件名(输出文件名): echo $0
  • 输出可执行文件的文件名(不输出路径):echo `basename $0`

    • 通过一个脚本进行多种操作：
      • 一个文件Calculation，进行文件名加减运算
        #! /bin/bash
fileName=`basename $0`
if [ $fileName = "add" ];then
result=$[$1+$2];
elif [ $fileName = "minus" ];then
result=$[$1-$2];
fi
echo "The $0 result is $result";
      • 然后进行一个链接
        ln -s Calculation add
ln -s Calculation minus
      • 加法运算
        # ./add 2 1
# The add result is 3
    • 减法运算
      # ./munis 2 1
# The munis result is 1
    • 特殊变量
      • 参数计数:$#
      • 所有参数:$*
      • 参数列表:$@
        #! /bin/bash
echo $#
echo $*
echo $@
 
for var in "$*"
do
echo "$* param is $var"
done
 
for var in "$@"
do
echo "$@ param is $var"
done

         

    • 测试输出结果：
    • 设置输入超时
      #! /bin/bash
if read -t 5 -p "input:" input
then
echo "you input: $input";
else
echo "Timeout";
fi