如何在 gcc 命令行中定义字符串文字?

2021-12-18 00:00:00 gcc c command-line macros c++

在gcc命令行中,我想定义一个字符串比如-Dname=Mary,然后在源代码中我想要printf("%s", name); 打印Mary.
我怎么办?

In gcc command line, I want to define a string such as -Dname=Mary, then in the source code I want printf("%s", name); to print Mary.
How could I do it?

推荐答案

两个选项.首先,对引号进行转义,这样 shell 就不会吃掉它们:

Two options. First, escape the quotation marks so the shell doesn't eat them:

gcc -Dname="Mary"

或者,如果你真的想要 -Dname=Mary,你可以将它字符串化,虽然它有点 hacky.

Or, if you really want -Dname=Mary, you can stringize it, though it's a bit hacky.

#include <stdio.h>

#define STRINGIZE(x) #x
#define STRINGIZE_VALUE_OF(x) STRINGIZE(x)


int main(int argc, char *argv[])
{
    printf("%s", STRINGIZE_VALUE_OF(name));
}

请注意,STRINGIZE_VALUE_OF 会很高兴地评估到宏的最终定义.

Note that STRINGIZE_VALUE_OF will happily evaluate down to the final definition of a macro.

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