错误：=：找不到命令（Bash 脚本）
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/23065722/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Error: =: command not found (Bash Script)
提问by Brian Schroeter
I found a nifty little shell script that I wanted to use from this website here.I have followed everything step-by-step, but receive the following error when running this on my CentOS box.
我在这里找到了一个漂亮的小 shell 脚本，我想从这个网站上使用它。我已经一步一步地遵循了一切，但是在我的 CentOS 机器上运行它时收到以下错误。
./deploy: line 3: =: command not found
Line 3 only contains...
第 3 行仅包含...
$ERRORSTRING = "Error. Please make sure you've indicated correct parameters"
I've tried toying around with a bit, but don't understand why it won't accept the "=" character. Is there something wrong with the script, or is it merely something different in the way that my server processes the script?
我试过玩弄一下，但不明白为什么它不接受“=”字符。脚本是否有问题，或者只是我的服务器处理脚本的方式不同？
Thanks!
谢谢！
回答by Gordon Davisson
Gah, that script is full of bad scripting practices (in addition to the outright error you're running into). Here's the outright error:
哎呀，该脚本充满了糟糕的脚本编写实践（除了您遇到的彻底错误之外）。这是彻底的错误：
$ERRORSTRING = "Error. Please make sure you've indicated correct parameters"
As devnull pointed out, this should be:
正如 devnull 所指出的，这应该是：
ERRORSTRING="Error. Please make sure you've indicated correct parameters"
A couple of lines down (and again near the end), we have:
几行下来（再次接近尾声），我们有：
echo $ERRORSTRING;
...which works, but contains two bad ideas: a variable reference without double-quotes around it (which will sometimes be parsed in unexpected ways), and a semicolon at the end of the line (which is a sign that someone is trying to write C or Java or something in a shell script). Use this instead:
...它有效，但包含两个坏主意：一个没有双引号的变量引用（有时会以意想不到的方式解析），以及行尾的分号（这是某人正在尝试的标志）在shell脚本中编写C或Java或其他东西）。改用这个：
echo "$ERRORSTRING"
The next line is:
下一行是：
elif [ == "live" ]
...which mightwork, depending on whether the value of $1has spaces, or is defined-but-blank, or anything like that (again, use double-quotes to prevent misparsing!). Also, the == comparison operator is nonstandard -- it'll work, because bash supports it in its [ ... ]builtin syntax, but if you're counting on having bash extensions available, why not use the much cleaner [[ ... ]]replacement? Any of these would be a better replacement for that line:
...这可能会起作用，具体取决于 的值是否$1有空格，或已定义但为空，或类似的东西（再次，使用双引号来防止错误解析！）。此外，== 比较运算符是非标准的——它可以工作，因为 bash 的[ ... ]内置语法支持它，但是如果您指望有可用的 bash 扩展，为什么不使用更干净的[[ ... ]]替代品呢？这些中的任何一个都可以更好地替代该行：
elif [ "" = "live" ]
elif [[ == "live" ]]
elif [[ "" == "live" ]]
Personally, I prefer the last. The double-quotes aren't needed in this particular case, but IMO it's safest to just double-quote all variable references unless there's a specific reason not to. A bit further down, there's a elif [ $2 == "go" ]that the same comments apply to.
就我个人而言，我更喜欢最后一种。在这种特殊情况下不需要双引号，但 IMO 最安全的是双引号所有变量引用，除非有特定原因不这样做。再往下一点，有一个elif [ $2 == "go" ]同样的评论适用。
BTW, there's a good sanity-checking tool for shell scripts at www.shellcheck.net. It's not quite as picky as I am (e.g. it doesn't flag semicolons at the ends of lines), but it pointed out all of the actual errors in this script...
顺便说一句，www.shellcheck.net 上有一个很好的 shell 脚本健全性检查工具。它不像我那么挑剔（例如它没有在行尾标记分号），但它指出了这个脚本中的所有实际错误......
回答by Brian Schroeter
"Devnulls" answer was correct -- I had to remove the spaces around the "=" and remove the "$" from that line as well. The end result was...
“Devnulls”答案是正确的——我必须删除“=”周围的空格并从该行中删除“$”。最终的结果是……
ERRORSTRING="Error. Please make sure you've indicated correct parameters"
I've upvoted Devnull and gniourf_gniourf's comments.
我赞成 Devnull 和 gniourf_gniourf 的评论。
Thank you to all whom have assisted!
感谢所有帮助过的人！
