请问，如下脚本中的PS3＝..是什么语法意思？

Hmilyade

请问，如下脚本中的“PS3=`Pls.select the number of student:`”是什么语法意思？

我执行脚本后的显示是这样的：
V1000-SNMPTest:/home/HXDE # sh indirect2.sh
1) S01
2) S02
3) S03
Pls. select the number of student:3
BASIC INFORMATION OF NO.S03 STUDENT:
NAME:Wang Ling
DEPARTMENThysical
PHONE:789
RANK:6
V1000-SNMPTest:/home/HXDE #



++++++++++++++++++++++++++++++++++++++++++++++++++
#!/bin/bash

S01_name="Li Hao"
S01_dept="Computer"
S01_phone="123"
S01_rank=5

S02_name="Zhang Ju"
S02_dept="English"
S02_phone="456"
S02_rank=6

S03_name="Wang Ling"
S03_dept="hysical"
S03_phone="789"
S03_rank=6

PS3=`Pls.select the number of student:`

select stunum in "S01" "S02" "S03"
do
        name=${stunum}_name
        dept=${stunum}_dept
        phone=${stunum}_phone
        rank=${stunum}_rank
        echo "BASIC INFORMATION OF NO.$stunum STUDENT:"
        echo "NAME{!name}"
        echo "DEPARTMENT{!dept}"
        echo "HONE{!phone}"
        echo "RANK{!rank}"
        break
done

waker

把`改成'

Hmilyade

哦，我错了，是单引号' '。

Hmilyade

#!/bin/bash

S01_name="Li Hao"
S01_dept="Computer"
S01_phone="123"
S01_rank=5

S02_name="Zhang Ju"
S02_dept="English"
S02_phone="456"
S02_rank=6

S03_name="Wang Ling"
S03_dept="Physical"
S03_phone="789"
S03_rank=6

PS3='Pls.select the number of student:'

select stunum in "S01" "S02" "S03"
do
        name=${stunum}_name
        dept=${stunum}_dept
        phone=${stunum}_phone
        rank=${stunum}_rank
        echo "BASIC INFORMATION OF NO.$stunum STUDENT:"
        echo "NAME:${!name}"
        echo "DEPARTMENT:${!dept}"
        echo "PHONE:${!phone}"
        echo "RANK:${!rank}"
        break
done

waker

PS3就是下面select命令的提示符