命令行参数
#./admin 10 30
读取参数
[root@localhost scrips]# vi test28.sh
#!/bin/bash
factorial=1
for ((number=1; number<=$1; number++))
do
factorial=$[ $factorial * $number ] #factorial=$(($factorial * $number))
done
echo "Then factorial of $1 is $factorial"
[root@localhost scrips]# bash test28.sh 5
Then factorial of 5 is 120
[root@localhost scrips]# vi test29.sh
#!/bin/bash
total=$(($1*$2))
echo "The first parameter is $1."
echo "The second parameter is $2."
echo "The total value is $total"
[root@localhost scrips]# bash test29.sh 2 5
The first parameter is 2.
The second parameter is 5.
The total value is 10
如果脚本需要的命令行参数不止个，你仍然可以处理，但是需要稍微修改一下变量名，在第9个变量之后，你必须在变量数字周围上花括号，经如${10}。
读取脚本名
#echo "The zero parameter is set to: $0" #$0是读取脚本名用的变量。
[root@localhost scrips]# vi test1a.sh
#!/bin/bash
name=$(basename $0)
echo
echo "The script name is: $name"
[root@localhost scrips]# bash test1a.sh
The script name is: test1a.sh
测试参数
[root@localhost scrips]# vi test2a.sh
#!/bin/bash
if [ -n "$1" ]
then
echo "Hello $1, glad to meet you."
else
echo "Sorry, you did not identify yourself"
fi
[root@localhost scrips]# bash test2a.sh
Sorry, you did not identify yourself
[root@localhost scrips]# bash test2a.sh 4
Hello 4, glad to meet you.
特殊参数变量
参数统计
$#示例
[root@localhost scrips]# vi file1.sh
#!/bin/bash
echo "There were $# parameters supplied."
[root@localhost scrips]# bash file1.sh 1 2 3 4 5
There were 5 parameters supplied.