shell之 函数（Function）
1、1、函数传入参数
[oracle@rhel6 zxx_shell]$ cat 2-function.sh
#!/bin/bash
function show_week()
{
local week1=$1 #表示将第一个参数传给本地变量week1
local week2=$2 #表示将第二个参数传给本地变量week2
declare -i total #表示声明一个整型变量
let total=$week1*$week2 #将变量week1和变量week2的乘积赋值给total
echo "week1=$week1"
echo "week2=$week2"
echo "total=$total"
}
show_week 3 4 #调用函数，调用时传入参数
[oracle@rhel6 zxx_shell]$ ./2-function.sh
week1=3
week2=4
total=12
2、2、函数通过全局变量返回值
[oracle@rhel6 zxx_shell]$ cat 2-function.sh
#!/bin/bash
total= #全局变量
function show_week()
{
local week1=$1 #local 表示本地变量
local week2=$2
total=$[$week1*$week2] #赋值给全局变量
}
num1=3
show_week $num1 "4"
echo "================="$total
[oracle@rhel6 zxx_shell]$ ./2-function.sh
=================12
3、3、函数通过echo返回值
[oracle@rhel6 zxx_shell]$ cat 2-function.sh
#!/bin/bash
function show_week()
{
local week1=$1
local week2=$2
let total=$week1*$week2
echo $total #通过echo标准输出返回函数值
}
num1=3
num2=$(show_week $num1 "4") #调用函数并将函数返回值赋值给变量
echo "================="$num2
[oracle@rhel6 zxx_shell]$ ./2-function.sh
=================12
4、4、函数相互调用
[oracle@rhel6 zxx_shell]$ cat 2-function.sh
#!/bin/bash
total=
function show_week()
{
local week1=$1
local week2=$2
total=$[$week1*$week2]
}
function getvalue()
{
num1=$1
num2=$2
show_week $num1 $num2 #调用show_week函数
echo "=================$total" #注意调用函数getvalue时，不 #会打印这个，它是作为返回值的
}
num3=3
num4=3
var=$(getvalue $num3 $num4)
echo "var string value is:$var"
[oracle@rhel6 zxx_shell]$ ./2-function.sh
var string value is:=================9
5、5、一个函数调用多个函数
[oracle@rhel6 zxx_shell]$ cat 2-function.sh
#!/bin/bash
function show_week()
{
local week1=$1
local week2=$2
total=$[$week1 * $week2] #传入参数的两个计算乘积，并返回
echo $total
}
function getvalue()
{
date1=`date +%w` #计算今天周几
echo $date1
}
function getchushu()
{
num1=$1
num2=$2
var1=$(show_week $num1 $num2)
var2=$(getvalue)
var3=$[$var1 / $var2] #计算两个函数返回值的除数
echo $var3
}
num3=5
num4=2
var4=$(getchushu $num3 $num4)
echo "var4 string value is:$var4"
[oracle@rhel6 zxx_shell]$ ./2-function.sh
var4 string value is:3
