如何在awk命令上传递参数？

I tried this but it does not seem to work. Please help thanks

我试过这个，但似乎没有用。请帮忙谢谢

 TEST_STRING= test

    echo Starting awk command
    awk -v testString=$TEST_STRING'
        BEGIN {

        }
    {
        print testString
        }
        END {}
    ' file2

1 个解决方案

#1

There are two problems here: You aren't actually assigning to TEST_STRING, and you're passing the program code in the same argument as the variable value. Both of these are caused by whitespace and quoting being in the wrong places.

这里有两个问题：您实际上并没有分配给TEST_STRING，而是在与变量值相同的参数中传递程序代码。这两个都是由空格和引用位于错误的地方引起的。

TEST_STRING= test

...does not assign a value to TEST_STRING. Instead, it runs the command test, with an environment variable named TEST_STRING set to an empty value.

...不为TEST_STRING赋值。相反，它运行命令test，将名为TEST_STRING的环境变量设置为空值。

Perhaps instead you want

也许你反而想要

TEST_STRING=test

要么

TEST_STRING=' test'

...if the whitespace is intentional.

......如果空白是故意的。

Second, passing a variable to awk with -v, the right-hand side should be double-quoted, and there must be unquoted whitespace between that value and the program to be passed to awk (or other values). That is to say:

其次，使用-v将变量传递给awk，右侧应该是双引号，并且该值与要传递给awk（或其他值）的程序之间必须有不带引号的空格。也就是说：

awk -v testString=$TEST_STRING' BEGIN

...will, if TEST_STRING contains no whitespace, pass the BEGIN as part of the value of testString, not as a separate argument!

...如果TEST_STRING不包含空格，则将BEGIN作为testString值的一部分传递，而不是作为单独的参数传递！

awk -v testString="$TEST_STRING" 'BEGIN

...on, the other hand, ensures that the value of TEST_STRING is passed as part of the same argument as testString=, even if it contains whitespace -- and ensures that the BEGIN is passed as part of a separate argument.

另一方面，... on确保TEST_STRING的值作为testString =的相同参数的一部分传递，即使它包含空格 - 并确保BEGIN作为单独参数的一部分传递。

#1