Linux进程管理之如何创建和销毁进程

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

int main() {
    pid_t child_pid;

    child_pid = fork();

    if (child_pid == 0) {
        // 子进程代码
        printf("This is the child process\n");
    } else if (child_pid > 0) {
        // 父进程代码
        printf("This is the parent process, child PID: %d\n", child_pid);
    } else {
        // 创建进程失败
        perror("fork");
        return 1;
    }

    return 0;
}

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

int main() {
    pid_t child_pid;

    child_pid = fork();

    if (child_pid == 0) {
        // 子进程代码
        printf("This is the child process\n");

        // 在子进程中执行新程序
        execl("/bin/ls", "ls", "-l", NULL);
    } else if (child_pid > 0) {
        // 父进程代码
        printf("This is the parent process, child PID: %d\n", child_pid);
    } else {
        // 创建进程失败
        perror("fork");
        return 1;
    }

    return 0;
}

#define _GNU_SOURCE
#include <stdio.h>
#include <sched.h>
#include <stdlib.h>
#include <unistd.h>

int child_function(void *arg) {
    printf("This is the child process\n");
    return 0;
}

int main() {
    char *stack;
    char *stack_top;
    pid_t child_pid;

    stack = (char *)malloc(8192);
    if (stack == NULL) {
        perror("malloc");
        return 1;
    }

    stack_top = stack + 8192;

    child_pid = clone(child_function, stack_top, CLONE_VM | CLONE_FS | CLONE_FILES, NULL);

    if (child_pid == -1) {
        perror("clone");
        return 1;
    }

    printf("This is the parent process, child PID: %d\n", child_pid);

    return 0;
}

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

int main() {
    pid_t child_pid;

    child_pid = fork();

    if (child_pid == 0) {
        // 子进程代码
        printf("This is the child process\n");

        // 子进程退出
        exit(0);
    } else if (child_pid > 0) {
        // 父进程代码
        printf("This is the parent process, child PID: %d\n", child_pid);

        // 等待子进程退出
        wait(NULL);

        printf("Child process has exited\n");
    } else {
        // 创建进程失败
        perror("fork");
        return 1;
    }

    return 0;
}

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

int main() {
    pid_t child_pid;

    child_pid = fork();

    if (child_pid == 0) {
        // 子进程代码
        printf("This is the child process (PID: %d)\n", getpid());

        // 创建一个新会话并成为会话领袖
        if (setsid() == -1) {
            perror("setsid");
            return 1;
        }

        // 创建一个新进程组
        if (setpgid(0, 0) == -1) {
            perror("setpgid");
            return 1;
        }

        printf("Child process is in a new session and process group\n");
        sleep(10); // 保持进程运行10秒
    } else if (child_pid > 0) {
        // 父进程代码
        printf("This is the parent process, child PID: %d\n", child_pid);

        // 等待子进程退出
        wait(NULL);

        printf("Child process has exited\n");
    } else {
        // 创建进程失败
        perror("fork");
        return 1;
    }

    return 0;
}

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

void sig_handler(int signo) {
    if (signo == SIGTERM) {
        printf("Received SIGTERM, exiting...\n");
        exit(0);
    }
}

int main() {
    pid_t child_pid;

    child_pid = fork();

    if (child_pid == 0) {
        // 子进程代码
        printf("This is the child process (PID: %d)\n", getpid());

        // 注册信号处理函数
        signal(SIGTERM, sig_handler);

        while (1) {
            // 子进程持续运行
            sleep(1);
        }
    } else if (child_pid > 0) {
        // 父进程代码
        printf("This is the parent process, child PID: %d\n", child_pid);

        // 等待一段时间后向子进程发送SIGTERM信号
        sleep(5);
        kill(child_pid, SIGTERM);
        printf("Sent SIGTERM to child process\n");

        // 等待子进程退出
        wait(NULL);

        printf("Child process has exited\n");
    } else {
        // 创建进程失败
        perror("fork");
        return 1;
    }

    return 0;
}