《Linux程序设计》第四版第二章 我的第一个shell程序：CD唱片应用程序

1. 书籍《Linux程序设计》第四版 Neil Mattew,Richard Stones著，第二章中书中用shell写了一个CD 唱片程序，仿照它，我自己大概实现了其功能，代码如下：

文件:manageCd.sh

#!/bin/bash
# this program aims to manage CD and songs contained in the CD
#	history:
#			2014-10-14  first release
# manageCd.sh
mainBoard()
{
choice=1
until [ $choice == "q" ]
do
clear
echo	"options as follow:"
echo "a) Add new CD"
echo "v) View CD"
echo "d) Delete CD"
echo "f) Find cd"
echo "c) Count the CD and songs in the catalog"
echo "u) update CD"
echo "q) quit"
echo ""

read -p "please input your choice: " choice
while [ "$choice" != "a" -a "$choice" != "v" -a "$choice" != "d" -a "$choice" != "f" -a "$choice" != "c" -a "$choice" != "u" -a "$choice" != "q" ]
do
read -p "input error,please input again([a,v,d,f,c,u]):" choice
done

case $choice in
"a")
addNewCD
;;

"v")
viewCD
;;

"d")
deleteCD
;;

"f")
findCD
;;

"c")
countCDAndSongs
;;

"u")
updateCD
;;

"*")
echo "error"
;;
esac
echo -n "press to return"
read x
done
}

addNewCD()
{
title_file="title_file"
songs_file="songs_file"

read -p "Enter CD name: " name
while true
do
flag=0
for x in `awk -F , '{print $1}' $title_file`
do
if [ "$name" == "$x" ]; then
echo -n "CD name:$name has existed,please input CD name again: "
read name
flag=1
break;
fi
done

if [ "$flag" == 0 ]; then
break;
fi
done

read -p "Enter CD Title: " title
read -p "Enter CD Type: " type
read -p "Enter The artist/composer: " composer

echo "About to add new entry"
echo  "$name  $title  $type  $composer"
read -p "Are you sure to add?(Y|y|N|n): " choice

while [ $choice != "y" -a $choice != "Y" -a $choice != "N" -a $choice != "n" ]
do
read -p "input error! please input again(Y,y,N,n): " choice
done

if [ $choice == "n" ]; then
echo "add cancelled"
return 1
fi

if [ -f $title_file ]; then
flag=1
else
flag=0
fi

if [ $flag == "1" ]; then  #file exists
echo "$name, $title, $type, $type, $composer" >> $title_file
else
touch $title_file    #create file
echo "$name, $title, $type, $type, $composer" > $title_file
fi

num=1
echo "Enter songs information for this CD:$name"
echo "When no more songs enter q"
while true
do
echo -n "song $num: song's name: "

while true
do
read songsname
if [ "$songsname" == "" ]; then
read -p "empty name,please input song's name again: " songsname
else
break;
fi
done

if [ "$songsname" == "q" ]; then
echo "add new CD finished! as follows: "
viewCD
return 0
fi

[ ! -f "$songs_file" ] && echo > "$songs_file" #to create empty file
echo "$name,$num,$songsname" >> "$songs_file"
num=`expr $num + 1`   # add 1
done

}

viewCD()
{
songs_file="songs_file"
title_file="title_file"
echo "file $title_file: "

if test -f "$title_file"; then
cat "$title_file" | more
else
echo "empty"
return 1
fi

echo ""

echo "file $songs_file: "
[ -f "$songs_file" ] && cat "$songs_file" | more
[ ! -f "$songs_file" ] && echo "empty" && return 1
echo ""

#awk -F , '{print $1}' "$title_file" #get the first row seperated by ,

for x in `awk -F , '{print $1}' "$title_file"`
do
echo "$x: " && grep "$x" "$songs_file"
echo ""
done

# read -p "input to return" abc
return 0
}

deleteCD()
{

title_file="title_file"
songs_file="songs_file"
read -p "please input CD name: " name
while [ "$name" == "" ]
do
read -p "no input,please input again: " name
done

echo "will delete CD $name..."
getConfirm &&
{
if grep "$name" $title_file; then

grep -v "$name" $title_file > tmpfile
mv tmpfile $title_file
grep -v "$name" $songs_file > tmpfile
mv tmpfile $songs_file
echo "delete CD name:$name finished!"
echo "CD contents:"
viewCD
#viewSongs
fi
}
return 0
}

findCD()
{
title_file="title_file"
songs_file="songs_file"
echo -n "please input CD name which you want to find: "
read cdname
while true
do
if [ "$cdname" == "" ]; then
echo -n "your input is empty,please input cd name again: "
read cdname
else
break
fi
done

[ ! -f "$title_file" ] && echo "no this cd: $cdname" && return 1

flag=0
for x in `awk -F , '{print $1}' $title_file`
do
if [ "$cdname" == "$x" ]; then
flag=1
grep "$cdname" $title_file
echo "songs in $cdname: "
[ -f "$songs_file" ] && grep "$cdname" $songs_file && flag=2
[ ! -f "$songs_file" ] && echo "this cd has no songs" && flag=3
# [ ! grep "$cdname" $songs_file ] && echo "this cd has no songs" && flag=3
break;
fi
done

if [ "$flag" == "0" ]; then
echo "no this cd: $cdname"
fi

}

getConfirm()
{
echo -n "Are you sure?"
while true
do
read x
case "$x" in
y|Y|yes|YES|Yes)
return 0;;

n|N|no|NO|No)
echo "cancelled"
return 1;;

*)
echo "please input yes or no";;
esac
done
}

countCDAndSongs()
{
title_file="title_file"
songs_file="songs_file"

cdnum=0
songnum=0
for x in `awk -F , '{print $1}' $title_file`
do
cdnum=`expr $cdnum + 1` # add 1
done

for x in `awk -F , '{print $1}' $songs_file`
do
songnum=`expr $songnum + 1` # add 1
done

echo "find $cdnum CDs,with a total of $songnum songs"
return 0

}

updateCD()
{
title_file="title_file"
songs_file="songs_file"
read -p "please input the CD name you want to update: " cdname
while true
do
if [ "$cdname" == "" ]; then
echo -n "empty input, please input again: "
read cdname
else
break
fi
done

flag=0
for x in `awk -F , '{print $1}' $title_file`
do
if [ "$cdname" == "$x" ]; then
flag=1
echo "this cd: "
echo " cdname   title    type    composer"
grep "$cdname" $title_file

echo "press enter to not update"

read -p "update the title?" cdtitle
read -p "update the type?"  cdtype
read -p "update the composer?" cdartist
if [ "$cdtitle" == "" -o "$cdtype" == "" -o "$cdartist" == "" ]; then
if [ "$cdtitle" == "" ]; then
cdtitle=`grep "$cdname" $title_file | awk -F , '{print $2}'`
fi

if [ "$cdtype" == "" ]; then
cdtype=`grep "$cdname" $title_file | awk -F , '{print $3}'`
fi

if [ "$cdartist" == "" ]; then
cdartist=`grep "$cdname" $title_file | awk -F , '{print $4}'`
fi
fi

grep -v "$cdname" $title_file > tmpfile
echo "$cdname,$cdtitle,$cdtype,$cdartist" >> tmpfile
mv tmpfile $title_file
echo "update finished! as follows: "
cat $title_file | more
break
fi
done

if [ "$flag" == "0" ]; then
echo "no this cd: $cdname"
fi

}
mainBoard

2. 运行：

  shell文件：manageCd.sh,保存唱片的文件：title_file,保存每个唱片对应歌曲的文件：songs_file

示例如下：

title_file: 各字段分别为：唱片名，标题，曲目类型，作曲家

CDname3,cool sax,type3,Bix

CDname2,classsic violin,type2,bach

songs_file:各字段分别为：唱片名，曲目编号，曲名

CDname2,1,good

CDname3,1,gsdf

CDname3,2,sff

截图：



功能：添加唱片，查看唱片，删除唱片，查找唱片，统计唱片和更新唱片