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【getpid/getppid系统调用】
功能描述: getpid返回当前进程标识,getppid返回父进程标识。用法: #include <sys/types.h> #include <unistd.h>
pid_t getpid(void);
pid_t getppid(void);例子:
#include <stdlib.h>
#include <stdio.h> #include <sys/types.h>int main(void)
{ pid_t pid; printf("Before fork ...\n"); switch(pid = fork()) { case -1: printf("Fock call fail\n"); exit(1); case 0: printf("The pid of child is: %d\n", getpid()); printf("The pid of child's parent is: %d\n", getppid()); printf("Child exiting...\n"); exit(0); default: printf("The pid of parent is: %d\n", getpid()); printf("the pid of parent's child is: %d\n", pid); } printf("After fork, program exiting...\n"); exit(0); }
getpid() getppid()进程和父进程函数
getpid()和getppid()进程和父进程函数,在调用中都不能返回错误,下面的程序输出了他的进程ID和父进程ID,由于不能保证pid_t 能够放进 int类型中去,返回值被转为long 整型输出
main()
{
#include <stdio.h>
#include <unistd.h>
printf ("I am process %ld",(long)getpid());
printf ("My parent is %ld",(long)getppid());
exit(0);
}
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