What does sleep mean in C language

The sleep function is used in C language to pause the specified number of seconds for program execution, and the syntax is sleep(unsigned int seconds). When seconds is 0, the function returns immediately, otherwise the function will pause the process for the specified number of seconds and return the actual paused time.

The meaning of sleep function in C language

The sleep function is a function provided in the C standard library to pause program execution for a specified period of time.

Function:

The sleep function will cause the calling process to pause the execution of the specified number of seconds. If the specified number of seconds is 0, the function returns immediately and does not pause program execution.

grammar:

 <code class="c">#include <unistd.h> unsigned int sleep(unsigned int seconds);</unistd.h></code>

in:

• seconds : The time to pause execution, in seconds.

Return value:

The sleep function returns the actual time to pause execution in seconds. If the pause time is less than one second, return 0.

Example:

 <code class="c">#include <stdio.h> #include <unistd.h> int main() { printf("程序开始执行。\n"); // 暂停执行5 秒sleep(5); printf("程序继续执行。\n"); return 0; }</unistd.h></stdio.h></code>

Output:

<code>程序开始执行。 // 暂停5 秒程序继续执行。</code>

Note:

• The sleep function is paused at the process level and will not affect the execution of other threads or processes.
• The sleep function cannot be used to accurately control the pause time, and the actual pause time may be slightly different from the specified time.
• When using sleep functions, be careful about the possibility of deadlocks, such as when multiple processes are waiting for each other.

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