作者:元菱淑亚禎盈 | 来源:互联网 | 2023-07-21 09:32
基本的操作增加删除查询展示全部学生信息vim编辑保存信息的文件遇到的问题1.增加学生信息时增加学生信息时,我用的echo重定向到文件里,这里开始用的一个>,会导致覆
基本的操作
- 增加
- 删除
- 查询
- 展示全部学生信息
- vim编辑保存信息的文件
遇到的问题
1.增加学生信息时
增加学生信息时,我用的echo重定向到文件里,这里开始用的一个>,会导致覆盖。以前的数据没有了。
总结:重定向符号:
>:覆盖型写法 (文件里原来的内容被覆盖)
echo "hello world" > myfile
>>:添加型写法 (新内容添加在原来内容的后面)
echo "hello world" >> myfile
2.删除某一行学生信息
开始不知道怎么删除,最后查到了grep -v命令。
他表示反向选择,亦即显示出没有 ‘搜寻字符串’ 内容的那一行。
具体实现代码
#! /bin/bash
search()
{
clear
echo -e "Please enter name >>>\c"
read NAME
if [ ! -f ./record ];then
echo "you must have some scores before you can search!"
sleep 2
clear
return
fi
if [ -z "$NAME" ];then
echo "you didn't enter a name!"
echo -e "Please enter name >>>\c"
read NAME
fi
grep -i "$NAME" ./record 2> /dev/null
case "$?" in
1) echo "Name not in record."
;;
2) echo "you didnt eter a name to search";
sleep 2;
search;;
esac
}
add()
{
clear
echo "Enter name and score of a record"
echo -e "\c"
if [ ! -f ./record ];then
touch record
fi
read NEWNAME
echo "$NEWNAME" >>./record
sort -o ./record ./record
}
delete()
{
clear
echo -e "Please enter delete name"
read NAME
if [ ! -f ./record ];then
echo "this name is not in record"
else
cp record record.bak
rm -f record
grep -v "$NAME" ./record.bak > record
rm -f record.bak
fi
}
display()
{
more ./record
}
edit()
{
vim ./record
}
help()
{
clear
echo "this is a student record program by unix shell language!"
}
quit()
{
clear
exit
}
clear
while true
do
echo "*********************************************"
echo "**** student record menu ****"
echo "*********************************************"
echo "---------------------------------------------"
echo "#############################################"
echo " 1-search a record "
echo " 2-add a record "
echo " 3-delete a record "
echo " 4-dispaly all records "
echo " 5-edit record with vim "
echo " H-help "
echo " Q-exit "
echo "#############################################"
echo -e -n "Please enter your choice [1,2,3,4,5,6,H,Q]:\c"
read CHOICE
case $CHOICE in
1) search;;
2) add; clear;;
3) delete; clear;;
4) display;;
5) edit; clear;;
H|h) help;;
Q|q) quit;;
*) echo "Invailid choice!";
sleep 2;
clear;;
esac
done