What do I have to include on a C program to use POSIX system calls?

必须包括一个C程序，使用POSIX系统调用什么呢？

youdao

I just indented code, pretty much as I would have done in a C program anyway, and it worked.

我只是用了缩进代码，就象我一直在C程序里所做的那样，这样足矣。

youdao

Last year the national program for playground safety gave the nation's playgrounds a grade of "C" for safety after visiting more than 3,000 playgrounds nationwide.

去年，国家游乐场安全计划在全国范围内走访了3000多个游乐场后，将国家游乐场的安全等级定为 “C” 级。

youdao

The I.O.C.says its efforts are the beginning of a worldwide tsunami-warning program.

VOA: special.2009.03.17

So it turns out that, main, yes, is the default function you write, at least in C, when writing a program.

结果是，main函数，是的，这是你写的默认函数，至少是在C语言中，当写程序的时候。

哈佛公开课 - 计算机科学课程节选

I'm going to open up a program called positive1.c. I'm going to scroll down to the juicy part here.

我将要打开一个叫做positive1，c的程序,我们翻到这个有趣的部分。

哈佛公开课 - 计算机科学课程节选

C. to announce the next round of a coordinated national program to improve fuel efficiency for cars and light-duty trucks for model years 2017 to 2025.

WHITEHOUSE: Press Briefing

The program then destroys a host of files based on file extension, specifically targeting C language code files, Microsoft Word, Excel and PowerPoint files, among others.

CNN: ExploreZip stings Marine Corps HQ - October 23, 19999

And building a very basic development tool might encourage more people to eventually learn how to program Objective-C, or whatever iPhone apps are coded with in the future, giving the iPhone platform a stronger farm system.

FORBES: Will Apple Respond To Google With "HyperCard For iPhone" App Tool?