瞭解Unix進程(3)

fork() 系統調用能夠建立新的進程。而後查看進程ID和父進程ID使用getpid()和getppid()函數.

使用C語言描述:

#include <unistd.h>
#include <stdio.h>

int 
main (int argc, char *argv[])
{
    pid_t child = -1;
    
    if ((child = fork()) == 0) {
        fprintf(stderr, "1: child pid is %u\n", getpid());
        fprintf(stderr, "2: his parent is %u\n", getppid());
    } else {
        fprintf(stderr, "3: parent pid is %u\n", getpid());
    }
    return 0;
}

運行結果: