linux kill c 残留

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

void child_process() {
    printf("Child process exiting.\n");
}

int main() {
    pid_t pid = fork();
    if (pid == 0) {
        child_process();
        exit(0);
    } else if (pid > 0) {
        int status;
        wait(&status); // 等待子进程结束并回收资源
        printf("Parent process: Child exited with status %d.\n", WEXITSTATUS(status));
    } else {
        perror("fork");
        return 1;
    }
    return 0;
}

#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>

void sigchld_handler(int signum) {
    int status;
    pid_t pid;
    while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
        printf("Child %d terminated.\n", pid);
    }
}

int main() {
    signal(SIGCHLD, sigchld_handler); // 设置信号处理函数
    pid_t pid = fork();
    if (pid == 0) {
        printf("Child process running.\n");
        sleep(5); // 模拟子进程工作
        exit(0);
    } else if (pid > 0) {
        printf("Parent process waiting.\n");
        sleep(10); // 父进程等待一段时间
    } else {
        perror("fork");
        return 1;
    }
    return 0;
}

#include <stdio.h>
#include <stdlib.h>

int main() {
    system("sleep 5; echo 'Child process finished.'");
    return 0;
}