在外壳程序中用双引号引起来的反引号 [英] Escape backquote in a double-quoted string in shell

问题描述

对于命令：/ usr / bin / sh -c ls 1`（1后的反引号）。

For the command: /usr/bin/sh -c "ls 1`" (a backquote after 1).

如何使其成功运行？在`之前添加反斜杠不起作用。
`是我们所知道的特殊字符，我也尝试用单引号将其括起来（/ usr / bin / sh -c ls 1'`'），但这也不起作用。

How to make it run successfully? Adding a backslash before "`" does not work. ` is a special char as we know, and I tried surrounding it with single quote too (/usr/bin/sh -c "ls 1'`'"), but that doesn't work either.

错误始终是：

% /usr/bin/sh -c "ls 1\`"
Unmatched `

推荐答案

您需要避开反引号，但也要避开反斜杠：

You need to escape the backtick, but also escape the backslash:

$ touch 1\`
$ /bin/sh -c "ls 1\\\`"
1`

必须逃跑的原因之所以说两次，是因为您是在一个环境中输入此命令的（例如shell脚本），该环境一次解释了双引号字符串。

The reason you have to escape it "twice" is because you're entering this command in an environment (such as a shell script) that interprets the double-quoted string once. It then gets interpreted again by the subshell.

您也可以避免使用双引号，从而避免第一种解释：

You could also avoid the double-quotes, and thus avoid the first interpretation:

$ /bin/sh -c 'ls 1\`'
1`

另一种方法是将文件名存储在变量中，并使用该值：

Another way is to store the filename in a variable, and use that value:

$ export F='1`'
$ printenv F
1`
$ /bin/sh -c 'ls $F'  # note that /bin/sh interprets $F, not my current shell
1`

最后，您尝试的内容将在某些shell上可用（对于上述示例，我使用的是bash），显然不是

And finally, what you tried will work on some shells (I'm using bash, as for the above examples), just apparently not with your shell:

$ /bin/sh -c "ls 1'\`'"
1`
$ csh  # enter csh, the next line is executed in that environment
% /bin/sh -c "ls 1'\`'"
Unmatched `.

我强烈建议您在第一名。

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