Linux C++ 错误：未在此范围内声明睡眠
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/10976176/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
C++ error : Sleep was not declared in this scope
提问by Mahika
I am using C++ in Ubuntu with codeBlocks, boost 1.46 in GCC 4.7 [ yield_k.hpp ]
我在 Ubuntu 中使用 C++ 和 codeBlocks，在 GCC 4.7 中提升 1.46 [yield_k.hpp]
I get this compile time error:
我收到此编译时错误：
error : Sleep was not declared in this scope
Code:
代码：
#include <iostream>
using namespace std;
int main() {
cout << "nitrate";
cout << flush;
sleep(1000);
cout << "firtilizers";
return 0;
}
How do I resolve this error? I want the program to hang for 1 second.
如何解决此错误？我希望程序挂起 1 秒钟。
采纳答案by moshbear
Sleepis a Windows function.
Sleep是一个 Windows 函数。
For Unix, look into using nanosleep(POSIX) or usleep(BSD; deprecated).
对于 Unix，请考虑使用nanosleep(POSIX) 或usleep(BSD；已弃用)。
A nanosleepexample:
一个nanosleep例子：
void my_sleep(unsigned msec) {
struct timespec req, rem;
int err;
req.tv_sec = msec / 1000;
req.tv_nsec = (msec % 1000) * 1000000;
while ((req.tv_sec != 0) || (req.tv_nsec != 0)) {
if (nanosleep(&req, &rem) == 0)
break;
err = errno;
// Interrupted; continue
if (err == EINTR) {
req.tv_sec = rem.tv_sec;
req.tv_nsec = rem.tv_nsec;
}
// Unhandleable error (EFAULT (bad pointer), EINVAL (bad timeval in tv_nsec), or ENOSYS (function not supported))
break;
}
}
You will need <time.h>and <errno.h>, available in C++ as <ctime>and <cerrno>.
您将需要<time.h>and <errno.h>，可在 C++ 中作为<ctime>and 使用<cerrno>。
usleepis simpler to use (just multiply by 1000, so make it an inline function). However, it's impossible to guarantee that that sleeping will occur for a given amount of time, it's deprecated, and you need to extern "C" { }-include <unistd.h>.
usleep使用起来更简单（只需乘以 1000，因此将其设为内联函数）。但是，无法保证在给定的时间内会发生睡眠，它已被弃用，您需要extern "C" { }-include <unistd.h>。
A third choice is to use selectand struct timeval, as seen in http://source.winehq.org/git/wine.git/blob/HEAD:/dlls/ntdll/sync.c#l1204(this is how wine emulates Sleep, which itself is just a wrapper for SleepEx).
第三种选择是使用selectand struct timeval，如http://source.winehq.org/git/wine.git/blob/HEAD:/dlls/ntdll/sync.c#l1204 中所见（这是 wine 模拟的方式Sleep，它本身只是一个包装SleepEx）。
Note: sleep(lowercase 's'), whose declaration is in <unistd.h>, is notan acceptable substitute, since its granularity is seconds, coarser than that of Windows' Sleep(uppercase 's'), which has a granularity of milliseconds.
注意：（sleep小写的 's'），其声明在 中<unistd.h>，不是可接受的替代品，因为它的粒度是秒，比Sleep粒度为毫秒的 Windows' （大写的 's'）粗。
Regarding your second error, ___XXXcallis a MSVC++-specific token (as are __dllXXX, __naked, __inline, etc.). If you reallyneed stdcall, use __attribute__((stdcall))or similar to emulate it in gcc.
关于第二个错误，___XXXcall是一个MSVC ++ -特定的令牌（因为是__dllXXX，__naked，__inline，等等）。如果您确实需要 stdcall，请使用__attribute__((stdcall))或类似的方法在 gcc 中模拟它。
Note: unless your compile target is a Windows binary andyou're using Win32 APIs, use of or a requirement for stdcallis A Bad Sign?.
注意：除非您的编译目标是 Windows 二进制文件并且您使用的是 Win32 API，否则使用或要求stdcall是 A Bad Sign?。
回答by Eric Leschinski
How to use usleep in a C++ program on linux:
如何在 Linux 上的 C++ 程序中使用 usleep：
Put this in a file called s.cpp
把它放在一个名为 s.cpp
#include <iostream>
#include <unistd.h>
using namespace std;
int main() {
cout << "nitrate";
cout << flush;
usleep(1000000);
cout << "firtilizers";
return 0;
}
Compile it and run it:
编译并运行它：
el@defiant ~/foo4/40_usleep $ g++ -o s s.cpp
el@defiant ~/foo4/40_usleep $ ./s
nitratefirtilizers
It printed 'nitrate', waited 1 second, then printed 'firtilizers'
它打印“硝酸盐”，等待 1 秒，然后打印“过滤剂”
回答by alex
In my case it helped to write Sleep and NOT sleep - very strange, but worked!
就我而言，它有助于编写Sleep 而不是sleep - 非常奇怪，但有效！
回答by alex
#include <iostream>
#include <unistd.h>
using namespace std;
int main()
{
const long a=1000000;
long j;
cin >> j;
usleep(a*j);
puts("exit");
}
use usleep()Insted of sleep and Don't forget to Include unistd.h(Not cunistd)
使用usleep()Insted of sleep 并且不要忘记包含unistd.h(Not cunistd)
