blocks|key|5241092|text|看起来你把"字符放错了地方。我不确定他们应该在哪里。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5241093|在第二行中，字符串文字：|5241094|"-U+$user_name+-P+$password+-S+$host+-d+master+-Q+"|code-block|syntax|javascript|5241095|紧跟在后面的是赤裸裸的|5241096|BACKUP|5241097|entityMap^0|5|1|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|W|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|X|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

Looks like you have your <code>"</code> characters in the wrong place. I'm not sure where they should be.

In your second line, the string literal:

<pre><code>"-U $user_name -P $password -S $host -d master -Q "
</code></pre>

is immediately followed by the bareword

<pre><code>BACKUP
</code></pre>

blocks|key|5149941|text|当字符串中有双引号时，您需要使用\对其进行转义。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5149942|$cmd+.=+"-U+$user_name+-P+$password+-S+$host+-d+master+-Q+\"BACKUP+DATABASE+[$database_name]+TO+DISK+=+N'$path'\"+";|code-block|syntax|javascript|5149943|此外，Perl允许您使用其他字符作为引号分隔符。qq后跟几乎任何字符都与双引号相同。因此，您可以这样做，以避免需要反斜杠：|5149944|$cmd+.=+qq(-U+$user_name+-P+$password+-S+$host+-d+master+-Q+"BACKUP+DATABASE+[$database_name]+TO+DISK+=+N'$path'"+);

$cmd+.=+qq%7C-U+$user_name+-P+$password+-S+$host+-d+master+-Q+"BACKUP+DATABASE+[$database_name]+TO+DISK+=+N'$path'"+%7C;|5149945|以此类推。|5149946|Perl：如何在中执行系统命令。有三种基本方法：|BOLD|5149947|system($cmd);++#Goes+through+the+shell+if+shell+metacharacters+are+detected.
system(@command_and_args);++#first+element+is+the+command,+the+rest+are+arguments|5149948|system执行一个命令并等待它返回。返回值是程序的退出状态。|5149949|my+@results+=+`$cmd`;++#Always+goes+through+shell.|5149950|Backticks执行命令并返回其输出。只有在实际需要输出时才应该使用它；否则，最好使用system。|5149951|exec+$cmd;
exec+@command_and_args;|5149952|exec和system完全一样，只是它永远不会返回。它通过调用另一个程序来有效地结束你的程序。|5149953|使用最适合您的情况的方法。或者，在本例中，由于您正在执行SQL，因此可以考虑使用DBI模块。对于任何比几个简单命令更好的方法，这绝对是一种更好的方法。|5149954|entityMap|0|LINK|mutability|MUTABLE|url|http://perldoc.perl.org/functions/system.html|1|http://perldoc.perl.org/perlop.html|2|http://perldoc.perl.org/functions/exec.html|3|http://dbi.perl.org/^0|G|1|0|0|O|2|0|0|0|8|G|0|0|0|V|0|6|0|6|0|0|0|0|1F|18|6|0|9|1|0|0|0|1B|0|4|0|4|2|0|0|23|14|3|3|0^^$0|@$1|2|3|4|5|6|7|1L|8|@$9|1M|A|1N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|1O|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1P|8|@$9|1Q|A|1R|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|1S|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1T|8|@]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1U|8|@$9|1V|A|1W|B|S]]|D|@]|E|$]]|$1|T|3|U|5|H|7|1X|8|@]|D|@]|E|$I|J]]|$1|V|3|W|5|6|7|1Y|8|@$9|1Z|A|20|B|S]|$9|21|A|22|B|C]]|D|@$9|23|A|24|1|25]]|E|$]]|$1|X|3|Y|5|H|7|26|8|@]|D|@]|E|$I|J]]|$1|Z|3|10|5|6|7|27|8|@$9|28|A|29|B|S]|$9|2A|A|2B|B|C]]|D|@$9|2C|A|2D|1|2E]]|E|$]]|$1|11|3|12|5|H|7|2F|8|@]|D|@]|E|$I|J]]|$1|13|3|14|5|6|7|2G|8|@$9|2H|A|2I|B|S]|$9|2J|A|2K|B|C]]|D|@$9|2L|A|2M|1|2N]]|E|$]]|$1|15|3|16|5|6|7|2O|8|@$9|2P|A|2Q|B|S]]|D|@$9|2R|A|2S|1|2T]]|E|$]]|$1|17|3|-4|5|6|7|2U|8|@]|D|@]|E|$]]]|18|$19|$5|1A|1B|1C|E|$1D|1E]]|1F|$5|1A|1B|1C|E|$1D|1G]]|1H|$5|1A|1B|1C|E|$1D|1I]]|1J|$5|1A|1B|1C|E|$1D|1K]]]]

When a string has double quotes within it, you need to escape them with <code>\</code>.

<pre><code>$cmd .= "-U $user_name -P $password -S $host -d master -Q \"BACKUP DATABASE [$database_name] TO DISK = N'$path'\" ";
</code></pre>

Also, Perl lets you use other characters for quote delimiters. <code>qq</code> followed by almost any character is the same as double quotes. So you could do things like this to avoid the need of backslashes:

<pre><code>$cmd .= qq(-U $user_name -P $password -S $host -d master -Q "BACKUP DATABASE [$database_name] TO DISK = N'$path'" );

$cmd .= qq|-U $user_name -P $password -S $host -d master -Q "BACKUP DATABASE [$database_name] TO DISK = N'$path'" |;
</code></pre>

And so on...

Update: How to execute a system command in Perl. There are three basic ways:

<pre><code>system($cmd); #Goes through the shell if shell metacharacters are detected.
system(@command_and_args); #first element is the command, the rest are arguments
</code></pre>

<a href="http://perldoc.perl.org/functions/system.html" rel="nofollow"><code>system</code></a> executes a command and waits for it to return. The return value is the exit status of the program.

<pre><code>my @results = `$cmd`; #Always goes through shell.
</code></pre>

<a href="http://perldoc.perl.org/perlop.html" rel="nofollow">Backticks</a> execute a command and return its output. You should only use this if you actually need the output; otherwise, it is better to go with <code>system</code>.

<pre><code>exec $cmd;
exec @command_and_args;
</code></pre>

<a href="http://perldoc.perl.org/functions/exec.html" rel="nofollow"><code>exec</code></a> is exactly like system, except that it never returns. It effectively ends your program by calling another program.

Use the one that is most appropriate to your situation. Or in this case, since you are executing SQL, consider using the <a href="http://dbi.perl.org/" rel="nofollow">DBI</a> module. It's definitely a better approach for anything more than a couple of simple commands.

This is my perl script code. in this i'm getting error like "bareword found where operator expected at $cmd"

<pre><code>my $path = $folder."/".$host."_".$database_name.".bak";
$cmd .= "-U $user_name -P $password -S $host -d master -Q "BACKUP DATABASE [$database_name] TO DISK = N'$path'" ";
</code></pre>

any one help me?

Perl Syntax Error: bareword found where operator expected

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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这是我的perl脚本代码。在这段代码中，我得到了类似于“在$cmd期望操作符的地方找到了”这样的错误。my $path = $folder."/".$host."_".$database_name.".bak";$cmd .= "-U $user_name -P $password -S $host -d master...

问Perl语法错误:在需要运算符的位置找到了空字
EN

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问Perl语法错误:在需要运算符的位置找到了空字EN