Shell编程之 函数

1、无参函数语法:

functionName(){

commands;

}

获取当前系统时间的函数

#!/bin/bash
#Get current date

getCurrentDate(){
current_date=`date --date="now" +%Y-%m-%d' '%H:%M:%S`;
cur_time=`date "+%Y-%m-%d %H:%M:%S"`;
echo $cur_time;
echo $current_date;
}

getCurrentDate

Notes：

1. 函数调用

直接使用函数名，如：getCurrentDate

2. 返回值

使用 echo，如：cur_time 和 current_date

2、有参函数语法:

functionName(){

arg1=$1;

arg2=$2;

arg3=0;

commands;

}

#!/bin/bash
#Fibonacci Sequence

echo "Press a number here..."
read number

if [ $number -le 0 ]
then
echo "You have something wrong.The number must be great then 0."
exit 1
fi
echo "Well, you wanna print between 1 and $number, and count them."

fibonacci(){
arg1=0
arg2=1
for((i=1;i<=$number;i++))
do
((arg3=$arg1+$arg2))

echo "Seq: $arg1+$arg2=$(($arg1+$arg2))"

sum=$(($sum+$arg3))
arg1=$arg2
arg2=$arg3
done

echo "$sum"
}
fibonacci