如何检查我的hadoop是否以伪分布式模式运行？(How to check if my hadoop is running in pseudo distributed mode?)

 else if这样的话，可以拆分else if ，你可以在if之前完成赋值。 
 
if (!strcmp(filename, "-"))
    cpio_list = stdin;
else {
        cpio_list = fopen(filename,"r")
        if (!cpio_list) { 
        ...
        ...
    }
}
 
 但是您可能需要重构一个函数，以便您可以在else之前return 。 
 
 就个人而言，只要加了括号（这意味着程序员的意思是它，它非常明显，并且抑制了编译器警告），偶尔的if-condition条件并不是什么大不了的事情。 

Split the else if so you can do the assignment before the if.
 
if (!strcmp(filename, "-"))
    cpio_list = stdin;
else {
        cpio_list = fopen(filename,"r")
        if (!cpio_list) { 
        ...
        ...
    }
}
 
But you might want to refactor out a function so that you can just return before the else.
 
Personally, I don't think it's a big deal to have an occasional assignment-in-if-condition as long as it is parenthesized (which means the programmer meant it, it stands out as obvious, and suppresses compiler warnings).