在Linux中将串行设备的I / O重定向到标准I / O的API是什么

Question

I am trying to port Vxworks application to Linux. For redirecting i/o of one of the serial device to standard i/o they are using ioTaskStdSet(); in vxworks. But I am not able to find the api in linux like as. Only duplicating device is available in linux that is also not working in my application.

Can anyone help me out in this?

Answer 1

As @Ignacio mentioned dup2 is used exactly for this purpose. For example this program redirect stdout to "echo" file:

#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>

int main(int argc, char *argv[]) {
    int fd = open("echo", O_RDWR | O_CREAT, 00644);
    if(fd == -1)
        return 1;

    if(dup2(fd, 1) == -1)
        return 1;
    close(fd);

    system("echo Hi!");
    return 0;
}

Answer 2

int main()
{
    for(i=0;i<4;i++)
    {
        sprintf(dev_name,"tsports%d",i);
        fd[i] = open(dev,O_RDWR | O_SYNC);
        pthread_create(tid[i],NULL,&thread_fun,(void *)fd[i]);
    }
    pthread_exit(NULL);
}
int thread_fun(void *chan)
{
     int new_fd,old_fd;
     old_fd = (int)chan;

     new_fd = dup2(old_fd,0);
     new_fd = dup2(old_fd,1);
     ts_fd = old_fd;
     tn();
     pthread_exit(NULL);
}
void tn()
{
     printf("hello on terminal");
     while(1)
     {
          read(ts_fd,&ch,1);
          /* command line */
          ........
          ........
          ........

          /* starts telnet client application on terminal port*/         
          .......
       ......
           ......
          .......
          sleep(1);
     }
}

 In the above code while taking input from terminal 1 it is again redirecting stdi/o to terminal 2 in second thread.

So i want thread specific stdi/o even though redirected on each terminal. That is available in Vxworks as IoTaskStdSet API. Is it possible to implement in linux.