"[[0:找不到命令]"；在巴什 [英] "[0: command not found" in Bash

问题描述

我试图在while循环中获取数组，并且也需要更新数组中的值.

I am trying to get the array in the while-loop and need to update the value in array too.

下面是我尝试的代码.我收到此错误[0: command not found

Below is my code what I have tried. I get this error [0: command not found

#!/bin/bash
i=0
while [$i -le "{#myarray[@]}" ]
do 
    echo "Welcome $i times"
    i= $(($i+1)))
done

我该如何解决?

推荐答案

赋值中[之后需要一个空格，在=之前或之后都不需要空格. $(($i+1)))会尝试执行((...))表达式的输出，我确定这不是您想要的.另外，您在数组名称前缺少$.

Need a space after [ and no space before or after = in the assignment. $(($i+1))) would try to execute the output of the ((...)) expression and I am sure that's not what you want. Also, you are missing a $ before the array name.

更正这些问题后，您的while循环将为:

With these things corrected, your while loop would be:

#!/bin/bash
i=0
while [ "$i" -le "${#myarray[@]}" ]
do 
  echo "Welcome $i times"
  i=$((i + 1))
done

• i=$((i + 1))也可以写为((i++))
• 总是最好在[ ... ]
中用双引号将变量引起来
• 通过 shellcheck 检查脚本-您可以在那里找到最基本的问题
• i=$((i + 1)) can also be written as ((i++))
• it is always better to enclose variables in double quotes inside [ ... ]
• check your script through shellcheck - you can catch most basic issues there

另请参阅:

• 为什么后面要有空格Bash中的[[和']之前?
• 如何使用双括号或单括号，括号，大括号
• 在Bash变量分配中未找到命令错误
• 在Bash if语句中使用[] vs [[]]
• Why should there be a space after '[' and before ']' in Bash?
• How to use double or single brackets, parentheses, curly braces
• Command not found error in Bash variable assignment
• Using [ ] vs [[ ]] in a Bash if statement

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