为什么这个shell命令出错 [英] why this shell command wrong

问题描述

find -name "*.c" -exec ls -l {} /;

它说缺少"-exec"的参数，
为什么呢〜?

请也告诉我最后的"/"是什么，谢谢

it says missing argument to ''-exec'',
why is that~?

Please tell me what is ''/'' at the end means as well, thanks

推荐答案

正确的行是:

The correct line would be:

find -name "*.c" -exec ls -l \{\} \;

或

or

find -name "*.c" -exec ls -l ''{}'' '';''

或

or

find -name "*.c" -exec ls -l ''{}'' \;

...
您看到图案了吗?

推理吗?

...
You see the pattern?

Reasoning?

1. shell将命令行分为多个块(第一个块是命令，其余的是命令的各个参数)
2. 由于壳本身是一种语言，因此它具有一些相关的标点符号和运算符-除其他外，{}和;对shell具有意义
3. ，因为find命令还需要进行{}和;的某些操作.作为自变量，必须确保{}和;不由外壳程序解释，而是传递给find命令.有两种方法可以实现:转义或放置到文字字符串中.
4. 转义是在一个字符前放置一个\-然后，该字符不被外壳解释并按原样传递(不加引号). \)
5. ''...''字符串在除去开头和结尾的单引号后按原样传递
6. "..."字符串由shell评估进行变量替换和其他功能，然后才能使用(通过删除引号)

1. the shell splits the command line into chunks (1st chunk is the command, the rest are the individual arguments to the command)
2. since the shell is a language in it self, it has some relevant punctuation and operator symbols - among others, { } and ; have a meaning to the shell
3. since the find command also needs for some operations the {} and ; as own arguments, one must make sure that the {} and the ; are not interpreted by the shell, but are rather passed to the find command. There are two possibilities to achieve that: escaping or placing into a literal string.
4. escaping is placing a \ before one character - the character then is not interpreted by the shell and is passed as-is (without leading \)
5. ''...'' strings are passed as-is, after stripping off the leading and trailing single quote
6. "..." strings get evaluated by the shell for variable substitution and other functions and only then are taken (by stripping off the quotes)

注意:如果希望将文本原样传递给命令，请使用单引号字符串(''...'').如果要放置{}或;到"{}"";;"中，它们由外壳程序解释，因此可能不会原样传递给find命令.

Note: If you want a text be passed unchanged to a command, use single quoted string (''...''). If you would place the {} or the ; into "{}" ";", they are interpreted by the shell and thus might not be passed unchanged to the find command.

您需要使用反斜杠来转义分号.这样的字符:

You need to use the backslash to escape the semi-colon character thus:

find -name "*.c" -exec ls -l {} \;

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