Shell variable problems

Shell variable problems-general Linux technology-Linux technology and application information, the following is a detailed description. [I = s] This post was last edited by theegg at, January 11 ,.

I have two shell files
1. main. sh
_ Active = 10; # value assignment
. Function. sh # Call the function File
Change_var # execution function

2. function. sh
Change_var (){
_ Active = 200;
}

I run main. sh

Why is the value of _ active not changed?
========================================================== ===
Thank you for your answers.
I will describe the problem in detail, because I was just learning shell and may not be able to describe it well.

1. I want to make a command to integrate all common commands, such as./ben. sh db-a add-d 'dbname ',
2. File structure
~ /Ben. sh
~ /Include/function/init. sh
~ /Include/function/db. sh
~ /Logs/
3. File Code

Ben. sh
-----------------------
#! /Bin/bash

###########################
# Ubuntu 10.10

###########################
# Init variable
Declare-a _ ITEMS = ('db' 'user' 'install ');

# Init db
Declare-a _ db_act = ('login' 'import' 'dump' 'drop' 'add' 'user ');
_ Db_active = 'login ';
Export _ db_active;
Declare-x _ db_user = 'root ';
Declare-x _ db_pass = '20140901 ';
Declare-x _ db_database = '';
Declare-x _ db_new_user = '';

# Init user

###########################
# Init function
. $ PWD/include/function/init. sh;

###########################
# Check User Permissions

_ USER_NAME = $ (whoami );
If [$ {_ USER_NAME} = 'root']; then
_ C_msg "----> ";
Else
_ C_msg "Current Login User $ {_ USER_NAME}, switch to root user ";
Exit 1;
Fi

#########################
# Parameters
For item in $ {_ ITEMS}
Do
If [$ item = $1]
Then
_ C_include "$ item ";
_ C_getopts "$ item ";
Fi
Done


Include/function/init. sh
----------------------------------
#! /Bin/bash

###########################
# Some common functions
# Output information
_ C_msg (){
Echo '-->' $1;
}

# Output logs
_ C_log (){
Echo "sdf ";
}

# Targeting parameters
_ C_getopts (){
_ $ Response getopts
}

# Load Functions
_ C_include (){
For file in $ (ls $ PWD/include/function/$1 /)
Do
If [-x $ file]
Then
Chmod 777 $ PWD/include/function/$1/$ file;
Fi
. $ PWD/include/function/$1/$ file;
Done;
}



~ /Include/function/db. sh
-------------------------------
#! /Bin/bash

# Parameter allocation
_ Db_getopts (){
Echo & quot; 123 & quot ";
While getopts a: u: p: d: nu: db_arg
Do
Case "$ db_arg" in
A) _ db_active =$ {OPTARG}; export _ db_active ;;
U) _ db_user =$ {OPTARG };;
P) _ db_pass =$ {OPTARG };;
D) _ db_database =$ {OPTARG };;
Nu) _ db_new_user =$ {OPTARG };;
Esac
Done
Echo $ _ db_active;
'_ Db _' "$ _ db_active ";
}

#############################
# Function
_ Db_help (){
Echo "-";
}

_ Db_install (){
Echo "-";
}

_ Db_login (){
Mysql-u $ {_ db_user}-p $ {_ db_pass };
}

_ Db_import (){
Echo "-";
}

_ Db_dump (){
Echo "-";
}

_ Db_drop (){
Echo "-";
}

_ Db_add (){
Mysql-u $ {_ db_user}-p $ {_ db_pass}-e "create database $ {_ db_datebase }"
}

_ Db_user (){
Echo "-";
}


4. Problem
When I run the./ben. sh db-a add-d test, _ db_active variable, the value cannot be obtained through the parameter. The same is true for other parameters. This variable is defined in the starting script. Can I assign a value in a subscript?

I beg you to give me some advice,