求解释一小段C语言代码的意思.#include#include#include#include/* This variable is a "global" variable that can be accessed by both a parent process and all of its child processes */int value = 0;/* Here is our "main" function,which is the
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求解释一小段C语言代码的意思.#include#include#include#include/* This variable is a "global" variable that can be accessed by both a parent process and all of its child processes */int value = 0;/* Here is our "main" function,which is the
求解释一小段C语言代码的意思.
#include#include#include#include/* This variable is a "global" variable that can be accessed by both a parent process and all of its child processes */int value = 0;/* Here is our "main" function,which is the entry point for the application in the C programming language:*/int main(int argc,const char * argv[]){ pid_t pid; // Here,we call the fork() function:what does this do?pid = fork(); if (pid == 0) /* child process */ { value = value + 1; printf ("CHILD:value = %d\n",value); /* LINE C */ } else if (pid > 0) /* parent process */ { wait(NULL); printf ("PARENT:value = %d\n",value); /* LINE P */ }}结果CHILD:1PARENT:0程序运行在linux环境下.求支援这段代码是干嘛的,是和进程线程有关.
求解释一小段C语言代码的意思.#include#include#include#include/* This variable is a "global" variable that can be accessed by both a parent process and all of its child processes */int value = 0;/* Here is our "main" function,which is the
这段代码主要是验证Unix\linux环境下通过fork()函数创建进程时,父子进程中的fork()函数会返回不同的值.
在程序执行完"pid = fork();"代码后,系统启动一个当前进程的“克隆进程”作为当前进程的子进程,
可以认为子进程与父进程一样,都“恰好”执行到fork代码行.
接下来父子进程的代码逻辑分叉,因为fork函数会在子进程中返回0值,而在父进程中返回子进程的pid值.
这也就是上述代码中,fork之后的两个if语句的意义：当pid==0时,说明当前代码属于子进程；而当pid>0时,说明当前代码属于父进程.