fork1.vfork.c

来自「Solaris下进程编程源码,sun公司培训用例」· C语言 代码 · 共 67 行

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>

int gvar = 0;

int main(int argc, char** argv)
{
        int lvar = 0;
        pid_t child_pid;
        
        printf("Initial value: gvar = %d, lvar = %d\n", gvar, lvar);
	        
        // Create the child process 1 using fork1()
        child_pid = fork1();
        switch(child_pid) {
        case -1:    // Error
                printf("Can't create child process 1\n");
                exit(-1);
        case 0:    // Child 1's code
                // Change the variables' value
                gvar = 1;
                lvar = 1;
                // Print the variables
                printf("Child process1: gvar = %d, lvar = %d\n", gvar, lvar);
		                                         
                printf("Press enter to exit child process 1...");
                getchar();
                exit(0);
        default:
                break;
        }
    
        // Wait for child 1's termination
        wait(NULL);
    
        // Print the global variable and local variable
        printf("Parent process: gvar = %d, lvar = %d\n", gvar, lvar);
        
        // Create the child process 2 using vfork()
        child_pid = vfork();
        switch(child_pid) {
        case -1:    // Error
                printf("Can't create child process 2\n");
                _exit(-1);
                break;
        case 0:    // Child 2's code
                // Change the variables' value
                gvar = 2;
                lvar = 2;
                // Print the variables
                printf("Child process2: gvar = %d, lvar = %d\n", gvar, lvar);
		                                                                                                                   
                printf("Press enter to exit child process 2...");
                getchar();
                _exit(0);
        default:
                break;
        }
    
        // Print the variables again
        printf("Parent process: gvar = %d, lvar = %d\n", gvar, lvar);
        return 0;
}