src/third_party/llvm-project/lldb/packages/Python/lldbsuite/test/functionalities/process_group/main.c

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

volatile int release_child_flag = 0;

int main(int argc, char const *argv[])
{
    pid_t child = fork();
    if (child == -1)
    {
        perror("fork");
        return 1;
    }

    if (child > 0)
    { // parent
        if (argc < 2)
        {
            fprintf(stderr, "Need pid filename.\n");
            return 2;
        }

        // Let the test suite know the child's pid.
        FILE *pid_file = fopen(argv[1], "w");
        if (pid_file == NULL)
        {
            perror("fopen");
            return 3;
        }

        fprintf(pid_file, "%d\n", child);
        if (fclose(pid_file) == EOF)
        {
            perror("fclose");
            return 4;
        }

        // And wait for the child to finish it's work.
        int status = 0;
        pid_t wpid = wait(&status);
        if (wpid == -1)
        {
            perror("wait");
            return 5;
        }
        if (wpid != child)
        {
            fprintf(stderr, "wait() waited for wrong child\n");
            return 6;
        }
        if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
        {
            fprintf(stderr, "child did not exit correctly\n");
            return 7;
        }
    }
    else
    { // child
        lldb_enable_attach();

        while (! release_child_flag) // Wait for debugger to attach
            sleep(1);

        printf("Child's previous process group is: %d\n", getpgid(0));
        setpgid(0, 0); // Set breakpoint here
        printf("Child's process group set to: %d\n", getpgid(0));
    }

    return 0;
}