Shell程式設計（1）

#!/bin/bash

choice=true
while [ "$choice" != [gG] ]
do
	printf '\n\nmenu:\n'
	printf '    A. List all files in the present directory\n'
	printf "    B. Display today's date and time\n"
	printf '    C. Display whether a file is a "simple" file or a "directory"\n'
	printf '    D. Create a backup for a file\n'
	printf "    E. Read user's id,then echo the username and the home dierectory\n"
	printf '    F. Delete the files ended of ".tmp" in the present directroy.\n'
	printf '    G. Exit\n'
	printf 'your choice:'
	read choice
	case "$choice" in
		[aA])
			ls -al ./*
			;;
		[Bb])
			printf 'time:'			
			date +%Y/%m/%d/%H:%M:%S
			;;
		[Cc])
			printf 'please input your file name:'
			read filename
			if [ -f "$filename" ] ; then
				printf '%s is a simple file' $filename
			elif [ -d "$filename" ] ; then
				printf '%s is a directory' $filename
			else
				printf '%s is not a simple file or directory' $filename
			fi
			;;
		[Dd])
			printf 'please input your file name:'
			read filename
			cp "$filename" ./"$filename"_backup && printf 'create backup succeed,and named %s_backup in the present directory' $filename || printf 'failed,maybe the file is not exsit'
			;;
		[Ee])
			printf 'please input your id number:'
			read idnumber
			printf 'the username and home directory :'
			grep ":$idnumber:[0-9]" /etc/passwd | cut -d ':' -f 1,6
			;;
		[Ff])
			rm -i ./*.tmp && printf 'deleted succeed' || printf 'there are not exsit the files whice ended of ".tmp" int the present directory'
			;;
		[Gg])
			break 
			;;
		*)
			printf 'please enter the correct character'
			;;
esac		
done
printf 'bye\n'
exit 0