在使用波浪号扩展的HOME目录下测试消极 [英] Getting negative on test for HOME directories with tilde ~ expansion

问题描述

特别是因为它在一个地方工作，而在另一个场景中不起作用。

>

我有他的代码检查这些目录是否存在 -
和与〜的HOME dirs在此代码片段中失败：

 如果[[！ -d$ valueToTest]];那么
 echo'Failed>>：'$ valueToTest; 
 fi; 
  

我得到输出：

 失败>>：〜/ .workspace / 
失败>>：〜/ .ssh 
失败>>：〜/ .workspace / vim / temp 
失败>>：〜/ .workspace / vim / backup 
失败>>：〜/ .workspace / vim 
失败>>：〜/ test 
  

像我说的那样，只有〜扩展代表我的HOME目录。

这是发生的唯一的地方，因为我有其他代码检查路径〜ie我的HOME目录与〜扩展，他们工作正常！

目录正在从关联数组的值部分读取 - 但是我看不出为什么会是一个问题。另外您可以看到输出没有引号或与之相关联。

我已尝试使用和不使用双引号 - 没有运气。

如下：

  $ valueToTest 
 $ {valueToTest} 
 $ {valueToTest}
  

感谢您的帮助。

解决方案

波浪号〜以任何方式引用时不会发生扩展。与路径名或文件扩展名称不同，〜也不会扩展，当它是变量的一部分。

如果 $ valueToTest 是〜/ .workspace / ，所有这些表单都不起作用：

 code> [[！ -d$ valueToTest]] 
 [[！ -d $ valueToTest]] 
 [！ -d $ valueToTest] 
  

而且只是：

 测试！ -d'〜/ .workspace /'
  

但是这样会有效：

 测试！ -d〜/ .workspace / 
  

或

 测试！ -d /home/user/.workspace/ 
  

所以修复你的代码是，你应该将扩展路径分配给您的变量，而不是未展开的形式：

  valueToTest =〜/ .workspace / ##正确分配。 
 valueToTest =〜'/。workspace /'##正确赋值。 
 valueToTest =〜/。workspace /##正确赋值。 
 
 valueToTest ='〜/ .workspace /'##分配不正确。 
 valueToTest =〜/ .workspace /##分配不正确。 
 
 set  - 〜/ .workspace / ##正确赋值。 
 valueToTest = $ 1 ##（模拟bash script.sh〜/ .workspace /）
 
 set  - 〜/ .workspace /##分配不正确。 
 valueToTest = $ 1 
  

Hack

如果不可避免只存储未展开的表单，可以使用 printf％q 和 eval 展开你的字符串到目前为止，我发现足够安全：

  printf -v temp％q$ valueToTest
 evalvalueToTest = $ temp
  

然后测试 $ valueToTest

更新

在Bash 4.3中， printf％q 也会引用波浪符号（〜）。要解决这个问题，可以让这些角色再次被引用：

  printf -v temp％q$ valueToTest
 temp = $ {temp // \\\〜/ \〜} 
 evalvalueToTest = $ temp
  

您还可以允许 $ HOME 展开：

  printf -v temp％q$ valueToTest
 temp = $ {temp // \\\\〜/ \〜} 
 temp = $ {temp // \ \\ $ HOME / \ $ HOME} 
 evalvalueToTest = $ temp
  

另一个可能的修复也是直接转换它们：

  valueToTest = $ {valueToTest // \〜/ $ HOME } 
 valueToTest = $ {valueToTest // \ $ HOME / $ HOME} 
  

I am getting a weird error, can't seem to figure out why.

Especially because it works in one place but not in another scenario.

I have his code that checks whether these directories exist - and the HOME dirs with ~ is failing in this code snippet:

if [[ ! -d "$valueToTest" ]]; then
    echo 'Failed>>:'$valueToTest;
fi;

I get output:

Failed>>:~/.workspace/
Failed>>:~/.ssh
Failed>>:~/.workspace/vim/temp
Failed>>:~/.workspace/vim/backup
Failed>>:~/.workspace/vim
Failed>>:~/test

Like I said it happens ONLY with the ~ expansion to represent my HOME directory.

And this is the ONLY place this is happening as I have OTHER code that checks for path with ~ ie my HOME directory with ~ expansion, AND they work fine!

The directories are being read from value part of an associative array - but I can't see why that would be a problem. Also you can see the output has no quotes or such associated with it.

I have tried with and without double-quotes - no luck.

As in:

$valueToTest
${valueToTest}
"${valueToTest}"

Thank you for help.

解决方案

Tilde expansion does not happen when ~ is quoted in any way. And unlike pathname or filename expansion, ~ also doesn't expand when it's part of a variable.

If $valueToTest is ~/.workspace/, all of these forms would not work:

[[ ! -d "$valueToTest" ]]
[[ ! -d $valueToTest ]]
[ ! -d $valueToTest ]

And is just synonymous to:

test ! -d '~/.workspace/'

But this would work:

test ! -d ~/.workspace/

Or

test ! -d /home/user/.workspace/

So the fix to your code is that, you should assign the expanded path to your variable instead, and not the unexpanded form:

valueToTest=~/.workspace/    ## Correct assignment.
valueToTest=~'/.workspace/'  ## Correct assignment.
valueToTest=~"/.workspace/"  ## Correct assignment.

valueToTest='~/.workspace/'  ## Incorrect assignment.
valueToTest="~/.workspace/"  ## Incorrect assignment.

set -- ~/.workspace/         ## Correct assignment.
valueToTest=$1               ## (simulates bash script.sh ~/.workspace/)

set -- "~/.workspace/"       ## Incorrect assignment.
valueToTest=$1

The Hack

If it's unavoidable that only the unexpanded form is stored, you can use printf %q and eval to expand your string. So far I find good enough and safe:

printf -v temp %q "$valueToTest"
eval "valueToTest=$temp"

Then test $valueToTest the way you do.

Update

In Bash 4.3, printf %q would already quote tilde characters (~) as well. To fix this you can make those characters unquoted again:

printf -v temp %q "$valueToTest"
temp=${temp//\\\~/\~}
eval "valueToTest=$temp"

You can also allow $HOME to expand:

printf -v temp %q "$valueToTest"
temp=${temp//\\\~/\~}
temp=${temp//\\\$HOME/\$HOME}
eval "valueToTest=$temp"

Another possible fix also is to just convert them directly:

valueToTest=${valueToTest//\~/$HOME}
valueToTest=${valueToTest//\$HOME/$HOME}

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