#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
int main(int argc, char *argv[])
{
    int fcp[2];
    int fpc[2];
    pid_t pid;
    if (pipe(fcp) == -1)
    {
        printf("pipe failed\n");
        return -1;
    }
    if (pipe(fpc) == -1)
    {
        printf("pipe failed\n");
        return -1;
    }
    if ((pid = fork()) != -1)
    {
        if (pid == 0)
        {
            // child
            // char const *arg[3];
            // arg[0] = "bc";
            // arg[1] = "-l";
            // arg[2] = NULL;
            close(fpc[1]);
            close(fcp[0]);
            char *buf = malloc(sizeof(char) * 1000);
            const char *prefix = "INPUT: ";
            memcpy(buf, prefix, strlen(prefix) + 1);
            read(fpc[0], buf + (strlen(prefix)), 1000 - strlen(prefix) - 1);
            write(fcp[1], buf, 1000);
            // execvp(arg[0], arg);
        }
        else
        {
            // parent
            close(fpc[0]);
            close(fcp[1]);
            const char *data = "testdata";
            char *buf = malloc(sizeof(char) * 1000);
            // write(fpc[1], data, strlen(data) + 1);
            FILE *fd = fopen(fpc[1], "w");
            fprintf(fd, "ddd");
            read(fcp[0], buf, 1000);
            printf("%s\n", buf);
        }
    }
}