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";

#! /bin/bash

fileName=`basename $0`

if [ $fileName = "add" ];then

result=$[$1+$2];

elif [ $fileName = "minus" ];then

result=$[$1-$2];

echo "The $0 result is $result";

然后进行一个链接

ln -s Calculation add ln -s Calculation minus

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ln -s Calculation add
ln -s Calculation minus
加法运算

# ./add 2 1 # The add result is 3

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# ./add 2 1
# The add result is 3

减法运算

# ./munis 2 1 # The munis result is 1

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# ./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
  
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  #! /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

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#! /bin/bash
if read -t 5 -p "input:" input
then
echo "you input: $input";
else
echo "Timeout";
fi

Strcpy²

Coding · Book · X²

Shell one of the basic applications