运维Shell脚本小试牛刀(四): 多层嵌套if...elif...elif....else fi

[运维Shell脚本小试牛刀(三):: $(cd$ (dirname $0)； pwd)命令详解](https://blog.csdn.net/u014635374/article/details/132579373 "运维Shell脚本小试牛刀(三)::$ (cd $(dirname$ 0)； pwd)命令详解")

运维Shell脚本小试牛刀(四): 多层嵌套if...elif...elif....else fi_蜗牛杨哥的博客-CSDN博客

一： if...elif...elif..else fi多层嵌套

$root@www dicfor\]# cat compareNumbers.sh #!/bin/bash - #================================================================================================================== # # # FILE: compareNumbers.sh # USAGE: ./compareNumbers.sh # DESCRIPTION: 演示逻辑与 \&\& 和逻辑或 \|\| # OPTIONS: ------- # REQUIREMENTS: --------- # # BUGS: ------ # NOTES: -------- # AUTHOR: ---------YangGe (TOM) ,YangGe.freedom@icloud.com # ORGANIZATION: # CREATED: 2023-8-29 09:11:20 # REVISION: -------- # # # # # #==================================================================================================================== # 如果指定的命令行参数个数不为1 ,则打印脚本的使用方法信息并退出脚本的运行，退出状态码为1 if \[ $# -ne 1$
then

打印脚本的使用信息

echo "Uage: 'basename $0' number"

退出脚本，状态码为1

exit 1

fi

将第一个命令行参数赋值给变量num

num=$1

如果$num值大于90 且小于100，则执行if语句的内容,否则执行elif的语句

if [ " $num" -ge 90 \] \&\& \[$ num -le 100 ]

then

打印Excellent

echo "Excellent......................!"

如果$num的值大于80 且小于 90, 则执行次elif语句中的内容, 否则执行下面的elif语句

elif [ $num -ge 80 \] \&\& \[$ num -lt 90 ]

then

打印Good...

echo "Good !............................................"

#如果大于等于60且小于80，则执行elif语句中的内容,否则执行下面的elif语句块,

elif [ $num -ge 60 \] \&\& \[$ {num} -lt 80 ]

then

打印"Pass mark!"

echo "Pass mark！......................................"

elif [ $num -lt 60 \] \&\& \[$ num -ge 0 ]

then

打印"Fail !"

echo "Fail!............................................"

如果上面的if条件和elif 条件语句都没有执行,则执行次else语句块

else

打印 "Wrong number........"

echo "Wrong number......................................"

fi

测试输出：
$root@www dicfor\]# ./compareNumbers.sh 2 Fail!............................................ \[root@www dicfor\]# ./compareNumbers.sh 2 334 Uage: 'basename ./compareNumbers.sh' number \[root@www dicfor\]# ./compareNumbers.sh 2 100 Uage: 'basename ./compareNumbers.sh' number \[root@www dicfor\]# ./compareNumbers.sh 2 90 Uage: 'basename ./compareNumbers.sh' number \[root@www dicfor\]# ./compareNumbers.sh 90 Excellent......................!$

#!/bin/bash -

#==================================================================================================================

FILE: checknumber.sh

USAGE: ./checknumber.sh

DESCRIPTION:

OPTIONS: -------

REQUIREMENTS: ---------

BUGS: ------

NOTES: --------

AUTHOR: ---------YangGe (TOM) ,YangGe.freedom@icloud.com

ORGANIZATION:

CREATED: 2023-8-24 09:11:20

REVISION: --------

#====================================================================================================================

如果指定的命令行参数个数等于0,则显示必须指定一个参数的提示信息,然后退出脚本,退出状态码为1

if [ $# -eq 0 ]

then

显示必须输入一个参数的提示信息

echo "$0 : You must give/supply one integers...."

退出脚本,退出状态码为1

exit 1;

fi

如果指定的参数大于0

if [ $1 -gt 0 ]

then

echo "The number is positive........"

如果指定的参数小于0

elif [ $1 -lt 0 ]

then

echo "The number is negative........"

如果指定的参数等于0

elif [ $1 -eq 0 ]

then

echo "The number is zero............"

else

echo "Opps! $1 is not number,please enter a number..."

fi

测试输出：
$root@www dicfor\]# ./checknumber.sh hhd ./checknumber.sh: 第 34 行:\[: hhd: 期待整数表达式 ./checknumber.sh: 第 40 行:\[: hhd: 期待整数表达式 ./checknumber.sh: 第 46 行:\[: hhd: 期待整数表达式 Opps! hhd is not number,please enter a number... \[root@www dicfor\]# ./checknumber.sh 2 The number is positive........ \[root@www dicfor\]# ./checknumber.sh -1111111111111 The number is negative........ \[root@www dicfor\]# ./checknumber.sh 0 The number is zero..........$