[shell:bash]: bash -- string and array

shell:  bash  --  string and array

 

 

 

 

一、源文件

[wit@ubuntu:null]$ cat  ./string_and_array 
#!/usr/bin/env bash




# file_name = string_and_array




# parameter
user_https='https://www.baidu.com/123.html'


echo -e  "\n\n"


echo  -e  "\n----  string cut: delete left part of string  ----\n"

echo  -e  "\tuser_https := "  ${user_https}

echo  -e  "\t"  '${user_https#*/} := '  ${user_https#*/}

echo  -e  "\t"  '${user_https##*/} := '  ${user_https##*/}




echo  -e  "\n----  string cut: delete right part of string  ----\n"

echo  -e  "\tuser_https := "  ${user_https}

echo  -e  "\t"  '${user_https%/*} := ' ${user_https%/*}

echo  -e  "\t"  '${user_https%%/*} := ' ${user_https%%/*}




# array


four="4"
user_array=('one'  'two'  'three'  $four  'five')


# output all elements
echo
echo  -e  "\n\n----  all elements of array  ----\n"
echo  -e  "\t"   '${user_array[@]} := ' ${user_array[@]}
echo  -e  "\t"   '${user_array[*]} := ' ${user_array[*]}


echo
echo  -e  "\n\n----  count_elements_of_array  ----\n"
# length(array()) = ${#user_array[@]}
# length(array()) = ${#user_array[*]}
echo  -e  "\t"  'length(user_array[@]) := ' ${#user_array[@]}
echo  -e  "\t"  'length(user_array[*]) := ' ${#user_array[*]}


echo
echo  -e  "\n\n---- output element of array ----\n"
# output specified element; ${user_array[1]} = user_array[1]
echo  -e  "\t"   '${user_array[1]} := ' ${user_array[1]}
echo  -e  "\t"  '${user_array[2]} := ' ${user_array[2]}


echo
echo  -e  "\n\n----  length_of_string  ----\n"
# length(string) = length(${user_array[1]})= ${#user_array[1]}
echo  -e  "\t"  "length(user_array[1]=${user_array[1]}) := " ${#user_array[1]}
echo  -e  "\t"  "length(user_array[3]=${user_array[2]}) := " ${#user_array[2]}
echo -e "\n\n"


[wit@ubuntu:null]$ 
[wit@ubuntu:null]$ 

 

 

 

 

二、运行实例

[wit@ubuntu:null]$ ./string_and_array 




----  string cut: delete left part of string  ----

        user_https :=  https://www.baidu.com/123.html
         ${user_https#*/} :=  /www.baidu.com/123.html
         ${user_https##*/} :=  123.html

----  string cut: delete right part of string  ----

        user_https :=  https://www.baidu.com/123.html
         ${user_https%/*} :=  https://www.baidu.com
         ${user_https%%/*} :=  https:



----  all elements of array  ----

         ${user_array[@]} :=  one two three 4 five
         ${user_array[*]} :=  one two three 4 five



----  count_elements_of_array  ----

         length(user_array[@]) :=  5
         length(user_array[*]) :=  5



---- output element of array ----

         ${user_array[1]} :=  two
         ${user_array[2]} :=  three



----  length_of_string  ----

         length(user_array[1]=two) :=  3
         length(user_array[3]=three) :=  5



[wit@ubuntu:null]$ 
[wit@ubuntu:null]$ 

 

 

 

 

三、参考文档

 

　　1、shell 变量 | 菜鸟教程 　　https://www.runoob.com/linux/linux-shell-variable.html