linux - 命令 "r--"命令的 UNIX Shell 脚本问题未找到

Question

我认为 if 语句将命令与文本进行比较而不是命令的输出，任何提示或帮助解决这个简单的问题

到目前为止我编写了这段代码:

    #!/bin/bash
echo -n "Enter File Name: "
read file

#Permission for the User Date
[ -w $file ] && W="yes" || W="No"

[ -x $file ] && X="yes" || W="No"

[ -r $file ] && R="yes" || R="No"

#Permission for the Group Data

grt= `ls -l $file | cut -c5-7`

if [ "grt" = "---" ]

 then

  grp="No No No"

elif [ "$grt" = "r--" ]

 then

  grp=" Yes No No"

elif [ "$grt" = "-w-" ]

 then

  grp="No Yes No"

elif [ "$grt" = "--x" ]

 then

  grp="No No Yes"

elif [ "$grt" = "rw-" ]

 then

  grp="Yes Yes No"

elif [ "$grt" = "r-x" ]

 then

  grp="Yes No Yes" 

elif [ "$grt" = "-wx" ]

 then

  grp="No Yes Yes"

fi

#Output

echo

echo "$file Properties"

echo

echo "        Read Write Execute"

echo "User:    $R   $W     $X"

echo "Group:   $grp"

Answer 1

你 shouldn't parse ls .如果有，请改用 stat。参见 BashFAQ/087有关获取文件元数据的信息。

您可以用 case 语句替换所有那些 if/elif 语句。

case "$grt" in
    "---") grp="No  No  No";;
    "r--") grp="Yes No  No";;
    . . .
esac

或者您可以映射字符串并在两个语句中完成所有操作(没有 if，没有 case):

grp=${grt//[rwx]/Yes }    # change any "r", "w" or "x" to "Yes "
grp=${grp//-/No  }         # change any "-" to "No  "