unix-脚本编写练习.ppt

写个从用户接受文件名的shell脚本。如果文件是普通文件，则显示以下信息： ————is an ordinary file-display? 如果答案是‘y’，而且文件是有可读权限的，显示文件，不 然，则显示如下信息并退出： sorry _______has no read permission. 如果参数是个目录，在用户确认了权限之后显示那个目录 里的文件名。 如果参数不是普通或者目录文件，显示出错信息并退出。 习题1 参考答案 Echo “enter a file or directory name:” Read fname If test -f ${fname} Then echo “${fname}is an ordinary file-diaplay?” Read ans If test $ans = ‘y’ Then if test –r ${fname} then cat ${fname} else echo “sorry,${fname} has no read permission” fi Fi Elif test -d ${fname} Then echo “${fname} is a directory file – display?” Read ans If test $ans = ‘y’ Then if test –r ${fname} then ls -l ${fname} else echo “sorry,${fname} has no read permission” fi Fi Else echo “${fname} is neither an ordinary file nor a directory” Fi 习题2 写个从用户接受一个文件名和一个目录名的shell脚本，脚本要检查文件和目录是否存在。如果存在，文件将被拷贝到指定的目录，如果文件或者目录不存在，显示错误信息。 写出shell脚本接受两个参数，开始时间和结束时间。然后显示所有在这段时间里登录的用户名。 习题 9 2:::::参考答案 Echo “enter file name” Read fn Echo “enter directory name” Read dn If test –f ${fn} Then if test –d ${dn} then cp ${fn} ${dn}/${fn} echo “file copies” else echo “directory does not exist ” fi Else echo “file does not exist” fi 9:::::参考答案 If test –z “$2” Then echo “you need to supply the start time and time as parameters” echo “USAGE: $0start_timeEnd_Time” echo “the time should be in hh:mm format –24 hour day” exit fi hour_after=`echo $1 | cut –d ‘:’ –f1` min_after=`echo $1 | cut –d ‘:’ –f2` total_after=`expr $hour_after \* 60` total_after=`expr $total_after + $min_after` hour_before=`echo $2 | cut –d ‘:’ –f1` min_before=`echo $2 | cut –d ‘:’ –f2` total_before=`expr $hour_after \* 60` total_before=`expr $total_before + $min_before` Echo “the following users have logged in between $1 and $2” Echo “-----------------------------------------------------------” For user in `who | tr –s ‘ ‘ | cut –d ‘ ‘` -f1,5 | tr ‘ ‘ ‘:’ ` Do Hour=`echo $user | cut –d ‘:’ –f2`