使用打印'%q'技术，我们可以运行一个循环来找出哪些字符是特殊的:

#!/bin/bash
special=$'`!@#$%^&*()-_+={}|[]\\;\':",.<>?/ '
for ((i=0; i < ${#special}; i++)); do
    char="${special:i:1}"
    printf -v q_char '%q' "$char"
    if [[ "$char" != "$q_char" ]]; then
        printf 'Yes - character %s needs to be escaped\n' "$char"
    else
        printf 'No - character %s does not need to be escaped\n' "$char"
    fi
done | sort

它给出如下输出:

No, character % does not need to be escaped
No, character + does not need to be escaped
No, character - does not need to be escaped
No, character . does not need to be escaped
No, character / does not need to be escaped
No, character : does not need to be escaped
No, character = does not need to be escaped
No, character @ does not need to be escaped
No, character _ does not need to be escaped
Yes, character   needs to be escaped
Yes, character ! needs to be escaped
Yes, character " needs to be escaped
Yes, character # needs to be escaped
Yes, character $ needs to be escaped
Yes, character & needs to be escaped
Yes, character ' needs to be escaped
Yes, character ( needs to be escaped
Yes, character ) needs to be escaped
Yes, character * needs to be escaped
Yes, character , needs to be escaped
Yes, character ; needs to be escaped
Yes, character < needs to be escaped
Yes, character > needs to be escaped
Yes, character ? needs to be escaped
Yes, character [ needs to be escaped
Yes, character \ needs to be escaped
Yes, character ] needs to be escaped
Yes, character ^ needs to be escaped
Yes, character ` needs to be escaped
Yes, character { needs to be escaped
Yes, character | needs to be escaped
Yes, character } needs to be escaped

有些结果，看起来有点可疑。获得@CharlesDuffy在这方面的投入会很有趣。

为了不让别人不得不RTFM…在bash中:

用双引号括起来的字符会保留引号内所有字符的文字值，除了$、'、\和(当启用历史扩展时)!

.．.所以如果你转义了这些(当然还有引用本身)，你可能就没事了。

如果你采取更保守的“当有疑问时，转义它”的方法，应该可以通过不转义标识符字符(即ASCII字母、数字或“_”)来避免获得具有特殊含义的字符。这是非常不可能的(即在一些奇怪的posix shell中)有特殊的含义，因此需要转义。

使用打印'%q'技术，我们可以运行一个循环来找出哪些字符是特殊的:

#!/bin/bash
special=$'`!@#$%^&*()-_+={}|[]\\;\':",.<>?/ '
for ((i=0; i < ${#special}; i++)); do
    char="${special:i:1}"
    printf -v q_char '%q' "$char"
    if [[ "$char" != "$q_char" ]]; then
        printf 'Yes - character %s needs to be escaped\n' "$char"
    else
        printf 'No - character %s does not need to be escaped\n' "$char"
    fi
done | sort

它给出如下输出:

No, character % does not need to be escaped
No, character + does not need to be escaped
No, character - does not need to be escaped
No, character . does not need to be escaped
No, character / does not need to be escaped
No, character : does not need to be escaped
No, character = does not need to be escaped
No, character @ does not need to be escaped
No, character _ does not need to be escaped
Yes, character   needs to be escaped
Yes, character ! needs to be escaped
Yes, character " needs to be escaped
Yes, character # needs to be escaped
Yes, character $ needs to be escaped
Yes, character & needs to be escaped
Yes, character ' needs to be escaped
Yes, character ( needs to be escaped
Yes, character ) needs to be escaped
Yes, character * needs to be escaped
Yes, character , needs to be escaped
Yes, character ; needs to be escaped
Yes, character < needs to be escaped
Yes, character > needs to be escaped
Yes, character ? needs to be escaped
Yes, character [ needs to be escaped
Yes, character \ needs to be escaped
Yes, character ] needs to be escaped
Yes, character ^ needs to be escaped
Yes, character ` needs to be escaped
Yes, character { needs to be escaped
Yes, character | needs to be escaped
Yes, character } needs to be escaped

有些结果，看起来有点可疑。获得@CharlesDuffy在这方面的投入会很有趣。

我猜你说的是bash字符串。有不同类型的字符串，它们对转义有不同的要求。如。单引号字符串不同于双引号字符串。

最好的参考是bash手册的引用部分。

它解释了哪些字符需要转义。注意，某些字符可能需要转义，这取决于启用了哪些选项，如历史扩展。

有两个简单而安全的规则，它们不仅可以在sh中工作，还可以在bash中工作。

1. 把整个字符串放在单引号中

这适用于所有字符，除了单引号本身。若要转义单引号，请关闭它前面的引号，插入单引号，然后重新打开引号。

'I'\''m a s@fe $tring which ends in newline
'

Sed命令:Sed -e "s/'/'\\\\ " /g;1年代/ ^ / /;\ s / \ /美元/”

2. 用反斜杠转义每个char

这适用于除换行符以外的所有字符。换行符使用单引号或双引号。空字符串仍然必须处理-替换为""

\I\'\m\ \a\ \s\@\f\e\ \$\t\r\i\n\g\ \w\h\i\c\h\ \e\n\d\s\ \i\n\ \n\e\w\l\i\n\e"
"

Sed命令:Sed -e 's/./\\&/g;1 {$ s / ^ $ / "};1 ! s / ^ /”;美元! s / /美元“/”。

2 b。更可读的版本2

有一组简单安全的字符，比如[a-zA-Z0-9，]。_+:@%/-]，可以不转义，以使其更具可读性

I\'m\ a\ s@fe\ \$tring\ which\ ends\ in\ newline"
"

sed命令:LC_ALL = C sed - e ' s / [^ a-zA-Z0-9 ,._+@%/-]/\\&/ g;1 {$ s / ^ $ / "};1 ! s / ^ /”;美元! s / /美元“/”。

注意，在sed程序中，不能知道输入的最后一行是否以换行符字节结束(除非换行符为空)。这就是为什么上面的sed命令都假设它不存在。您可以手动添加带引号的换行符。

注意，外壳变量仅为POSIX意义上的文本定义。没有定义如何处理二进制数据。对于重要的实现，二进制除了NUL字节(因为变量是用C字符串实现的，意味着被用作C字符串，即程序参数)，但您应该切换到“二进制”语言环境，例如latin1。

(你可以通过阅读sh的POSIX规范来验证规则。对于bash，查看@AustinPhillips链接的参考手册)

我注意到bash在使用自动完成时自动转义一些字符。

例如，如果你有一个名为dir: a的目录，bash会自动补全到dir\: a

使用这个，我运行了一些实验，使用ASCII表的字符，并推导出以下列表:

bash自动完成转义的字符:(包括空格)

 !"$&'()*,:;<=>?@[\]^`{|}

bash没有转义的字符:

#%+-.0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz~

(我排除了/，因为它不能在目录名中使用)