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开始学习shell 脚本的 应用举例
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简单的CD管理系统
实现功能： 添加CD——a）增加CD的同时给CD增加相应的曲目信息
删除CD——r）删除指定的CD
查找CD——f）查找指定的CD
更新CD——u）更新指定CD中的曲目信息——重新给该CD添加曲目信息
显示CD——l）显示当前指定CD的曲目信息
统计CD——c）统计有多少张CD，共有多少曲目
退出CD——q）退出CD管理系统
代码：
============================= 代码开始 ===============================
#!/bin/bash
#### global variable define strat ####
menu_choice=""
current_cd=""
title_file="title.cdb" #保存CD的信息，包括CD号码，CD标题，CD类型，CD作者
tracks_file="tracks.cdb"
#保存所有曲目信息，包括CD号码，曲目号码——每张CD由1开始，曲目名称
temp_file=/tmp/cdb.$$ #临时文件
trap `rm -rf $temp_file` EXIT #遇到中断时删除临时文件
#### global variable define end ####
#### function define about tools start ####
get_return() #返回值函数，需要用户输入需要的返回值，0正常，非0异常
{
echo -e "Press return: \c" #显示字符串信息
read x #给变量x读入一个值
return 0
}
get_confirm() #确认函数，需要用户输入yes或者no或者y或者n
{
echo -e "Are you sure? \c"
while true
do
read x
case "$x" in
y | yes | Y | Yes | YES) return 0;;
n | no | N | No | NO) echo
echo "Cancelled"
return 1;;
*) echo -e "Please enter yes or no: \c";;
esac
done
}
#### function define about tools end ####
#### set menu chocie function start ####
set_menu_choice() #每次操作选项的显示
{
# clear
echo "Options :-"
echo
echo " a) Add new CD"
echo " f) Find CD"
echo " c) Count the CDs and tracks in the catalog"
if [ "$cdcatnum" != "" ];then #当前环境有对CD的操作
echo " l) List tracks on $cdtitle"
echo " r) Remove $cdtitle"
echo " u) Update track information for $cdtitle"
fi
echo " q) Quit"
echo
echo -e "Please enter choice the press return: \c"
read menu_choice #读入用户输入的操作选项
return
}
#### set menu chocie function end ####
#### insert and add opration start ####
insert_title()
{
echo $* >> $title_file #将该函数的所有参数输入到文件
return
}
insert_track()
{
echo $* >> $tracks_file
return
}
add_record_tracks()
{
echo "When no more tracks enter q"
echo "Enter track information for this CD"
cdtrack=1
cdttitle=""
while [ "$cdttitle" != "q" ]
do
echo -e "Track $cdtrack, track title? \c"
read tmp
cdttitle=${tmp%%,*} #不能输入含有逗号的曲目名称
if [ "$tmp" != "$cdttitle" ]; then
echo "Sorry, no commas allowed"
continue
fi
if [ -n "$cdttitle" ]; then
if [ "$cdttitle" != "q" ]; then
insert_track $cdcatnum,$cdtrack,$cdttitle #调用函数，插入曲目信息
fi
else
cdtrack=$((cdtrack-1)) #当为q时，上次运行已经加1，所以做减一操作
fi
cdtrack=$((cdtrack+1)) #曲目号码自动累加
done
}
add_records()
{
#Prompt for the initial infomation
echo -e "Enter catalog name: \c"
read tmp
cdcatnum=${tmp%%,*}
echo -e "Enter title: \c"
read tmp
cdtitle=${tmp%%,*}
echo -e "Enter type: \c"
read tmp
cdtype=${tmp%%,*}
echo -e "Enter arrist or composer: \c"
read tmp
cdac=${tmp%%,*}
#Check that they want to enter the infomation
echo "About to add new entry"
echo "$cdcatnum, $cdtitle, $cdtype, $cdac" #显示变量的值的方式
#If confirmed then append it to the titles file
if get_confirm; then
insert_title $cdcatnum,$cdtitle,$cdtype,$cdac #添加CD信息
add_record_tracks #给该CD添加曲目信息——需要一次性添加完毕
else
remove_records #调用删除函数
fi
return
}
#### insert and add opration end ####
#### list track start ####
list_tracks()
{
if [ "$cdcatnum" = "" ]; then
echo "no CD selected yet"
return
else
grep "^${cdcatnum}," $tracks_file > $temp_file
#在曲目文件中查找以CD号码开始以逗号结束的曲目信息，并将非此信息输出到临时文件
set $(wc -l $temp_file) #设置位置参数为统计曲目的个数信息
num_tracks=$1 #即该位置参数是曲目的个数
if [ "num_tracks" = "0" ]; then
echo "no tracks found for $cdtitle"
else {
echo
echo "$cdtitle :-"
echo
cut -f 2- -d , $temp_file
#输出临时文件中曲目的后两项信息，即曲目号码，曲目名称
echo
} | ${PAGER:-more} #分页显示
fi
fi
get_return
return
}
#### list tracks end ####
#### find CD start ####
find_cd() #该函数需要一个参数，表示是否显示查询到的CD的曲目信息
{
if [ "$1" = "n" ]; then
asklist=n #不显示
else
asklist=y #显示
fi
cdcatnum=""
echo -e "Enter a string to search for in the CD titles: \c"
read searchstr
if [ "searchstr" = "" ]; then
return 0
fi
grep "$searchstr" $title_file > $temp_file
#在CD文件中查找指定标题的信息存储到临时文件中
set $(wc -l $temp_file)
linesfound=$1
case "$linesfound" in
0) echo "Sory, nothing found"
get_return
return 0
;;
1) ;;
2) echo "Sorry, not unique"
echo "Found the following"
cat $temp_file
get_return
return 0
esac
IFS="," #修改默认选项，改为以逗号为分隔符
read cdcatnum cdtitle cdtype cdac < $temp_file
#从临时文件以逗号为分隔符一次读入需要的CD信息选项
IFS=" " #恢复默认设置
if [ -z "$cdcatnum" ]; then #变量cdcatnum是否是0，是0时返回true
echo "Sorry, could not extract catalog field from $temp_file"
get_return
return 0
fi
echo
echo "Catalog number: $cdcatnum"
echo "Title: $cdtitle"
echo "Type: $cdtype"
echo "Artist or Composer: $cdac"
echo
get_return
if [ "$asklist" = "y" ]; then
echo -e "View tracks for this CD? \c"
read x
if [ "$x" = "y" ]; then
echo
list_tracks
echo
fi
fi
return 1
}
#### find CD end ####
#### update CD start ####
update_cd()
{
if [ -z "$cdcatnum" ]; then
echo "You must select a CD first"
find_cd n
fi
if [ -n "$cdcatnum" ]; then #变量cdcatnum非null吗，是返回true
echo "Current tracks are :-"
list_tracks
echo
echo "This will re-enter the tracks for $cdtitle"
get_confirm && {
grep -v "^${cdcatnum}," $tracks_file > $temp_file
mv $temp_file $tracks_file #删除不需要的曲目信息，并更新曲目文件
echo
add_record_tracks #更新曲目信息
}
fi
return
}
#### update CD end ####
#### count CD start ####
count_cds()
{
set $(wc -l $title_file) #统计CD的个数
num_titles=$1
set $(wc -l $tracks_file) #统计曲目的个数
num_tracks=$1
echo "Found $num_titles CDs, with a total of $num_tracks tracks"
get_return
return
}
#### count CD end ####
#### remove records start ####
remove_records()
{
if [ -z "$cdcatnum" ]; then
echo "You must select a CD first"
find_cd n
fi
if [ -n "$cdcatnum" ]; then
echo "You are about to delete $cdtitle"
get_confirm && {
grep -v "^${cdcatnum}," $title_file > $temp_file
mv $temp_file $title_file #删除CD文件中不需要的CD信息
grep -v "^${cdcatnum}," $tracks_file > $temp_file
mv $temp_file $tracks_file #删除曲目文件中不需要的曲目信息
cdcatnum=""
echo "Entey removed"
}
fi
return
}
#### remove records end ####
#### main start ####
rm -rf $temp_file #先删除临时文件
if [ ! -f $title_file ]; then #判断CD文件非普通文件吗？是返回true
touch $title_file #创建该CD文件
fi
if [ ! -f $tracks_file ]; then #同理判断曲目文件
touch $tracks_file
fi
#Now the application proper
echo
echo
echo "Mini CD manager"
sleep 1
quit=n
while [ "$quit" != "y" ]
do
set_menu_choice #显示选项操作项，并给变量menu_choice读入值
case "$menu_choice" in
a) add_records;;
r) remove_records;;
f) find_cd y;;
u) update_cd;;
c) count_cds;;
l) list_tracks;;
b)
echo
more $title_file
echo
get_return;;
q | Q) quit=y;;
*) echo "Sorry, choice not recognized";;
esac
done
#Tidy up and leave
rm -f $temp_file #删除临时文件
echo "Finished"
exit 0
#### main end ####
=============================== 代码结束 ==============================
运行结果：
[root@localhost shell]# chmod +x cdmanager.sh //给shell添加执行权限
[root@localhost shell]# ./cdmanager.sh //运行该shell
Mini CD manager
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
q) Quit
Please enter choice the press return: a——输入a表示添加CD
Enter catalog name: CD88——输入CD88表示CD的编号
Enter title: myCD88——输入myCD88 表示CD88的标题
Enter type: liu_xing——输入liu_xing 表示CD88上的曲目类型
Enter arrist or composer: zhou_jie_lun——输入zhou_jie_lun 表示CD88的作曲家
About to add new entry
CD88, myCD88, liu_xing, zhou_jie_lun——显示添加信息，以便确认
Are you sure? y ——输入y表示确认无误
When no more tracks enter q
Enter track information for this CD
Track 1, track title? ju_hua_tai——输入CD88的曲目
Track 2, track title? huang_jin_jia——输入CD88的曲目
Track 3, track title? qian_li_zhi_wai——输入CD88的曲目
Track 4, track title? shuan_jie_gun——输入CD88的曲目
Track 5, track title? dong_feng_po——输入CD88的曲目
Track 6, track title? q——退出该CD88曲目的录入
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD88
r) Remove myCD88
u) Update track information for myCD88
q) Quit
Please enter choice the press return: l——输入l，显示当前CD的曲目信息
myCD88 :-
1,ju_hua_tai
2,huang_jin_jia
3,qian_li_zhi_wai
4,shuan_jie_gun
5,dong_feng_po
Press return: 0——输入一个返回值，0表示正常，非0表示异常
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD88
r) Remove myCD88
u) Update track information for myCD88
q) Quit
Please enter choice the press return: c——统计CD总数和曲目总数
Found 1 CDs, with a total of 5 tracks
Press return: 0——输入一个返回值，0表示正常，非0表示异常
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD88
r) Remove myCD88
u) Update track information for myCD88
q) Quit
Please enter choice the press return: a——添加CD信息
Enter catalog name: CD77
Enter title: myCD77
Enter type: gu_dian
Enter arrist or composer: yue_guang
About to add new entry
CD77, myCD77, gu_dian, yue_guang
Are you sure? q——输入参数错误
Please enter yes or no: yes——应该输入为yes或者no
When no more tracks enter q
Enter track information for this CD
Track 1, track title? yue_guang——添加当前CD的曲目信息
Track 2, track title? q——曲目信息添加结束
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD77
r) Remove myCD77
u) Update track information for myCD77
q) Quit
Please enter choice the press return: c——统计CD总个数和曲目总数
Found 2 CDs, with a total of 6 tracks
Press return: 0
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD77
r) Remove myCD77
u) Update track information for myCD77
q) Quit
Please enter choice the press return: f——查找指定CD标题的CD
Enter a string to search for in the CD titles: myCD88——指定的CD标题为myCD88
Catalog number: CD88 ——显示该CD的信息
Title: myCD88
Type: liu_xing
Artist or Composer: zhou_jie_lun
Press return: 0
View tracks for this CD? y——显示该CD的曲目信息吗
myCD88 :- ——该CD曲目信息的显示
1,ju_hua_tai
2,huang_jin_jia
3,qian_li_zhi_wai
4,shuan_jie_gun
5,dong_feng_po
Press return: 0
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD88
r) Remove myCD88
u) Update track information for myCD88
q) Quit
Please enter choice the press return: l——显示当前CD的曲目信息
myCD88 :-
1,ju_hua_tai
2,huang_jin_jia
3,qian_li_zhi_wai
4,shuan_jie_gun
5,dong_feng_po
Press return: 0
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD88
r) Remove myCD88
u) Update track information for myCD88
q) Quit
Please enter choice the press return: u——更新当前的CD曲目信息
Current tracks are :-
myCD88 :-
1,ju_hua_tai
2,huang_jin_jia
3,qian_li_zhi_wai
4,shuan_jie_gun
5,dong_feng_po
Press return: 0
This will re-enter the tracks for myCD88
Are you sure? n——确认是否更新该CD
Cancelled
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD88
r) Remove myCD88
u) Update track information for myCD88
q) Quit
Please enter choice the press return: f
Enter a string to search for in the CD titles: myCD77
Catalog number: CD77
Title: myCD77
Type: gu_dian
Artist or Composer: yue_guang
Press return: 0
View tracks for this CD? n——显示该CD的曲目信息吗
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD77
r) Remove myCD77
u) Update track information for myCD77
q) Quit
Please enter choice the press return: u
Current tracks are :-
myCD77 :-
1,yue_guang
Press return: 0
This will re-enter the tracks for myCD77
Are you sure? y——确认更新该CD的曲目信息（相当于该CD的曲目信息从新输入）
When no more tracks enter q
Enter track information for this CD
Track 1, track title? bei_duo_fen
Track 2, track title? shu_bo_te
Track 3, track title? q
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD77
r) Remove myCD77
u) Update track information for myCD77
q) Quit
Please enter choice the press return: l
myCD77 :-
1,bei_duo_fen
2,shu_bo_te
Press return: 0
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
l) List tracks on myCD77
r) Remove myCD77
u) Update track information for myCD77
q) Quit
Please enter choice the press return: r——删除当前的CD
You are about to delete myCD77
Are you sure? y——确认删除当前CD
Entey removed
Options :-
a) Add new CD
f) Find CD
c) Count the CDs and tracks in the catalog
q) Quit
Please enter choice the press return: f
Enter a string to search for