tcdropline()

Updated: May 06, 2022

Disconnect a communications line

Synopsis:

#include <termios.h>

int tcdropline( int filedes, 
                int duration );

Arguments:

filedes
A file descriptor that's associated with the line that you want to disconnect.
duration
The number of milliseconds that you want to drop the line for.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The tcdropline() function initiates a disconnect condition on the communication line associated with the opened file descriptor indicated by filedes.

The disconnect condition lasts at least duration milliseconds, or approximately 300 milliseconds if duration is zero. The system rounds the effective value of duration up to the next highest supported interval, which is typically a multiple of 100 milliseconds.

Returns:

0
Success.
-1
An error occurred (errno is set).

Errors:

EBADF
Invalid filedes argument.
ENOSYS
The resource manager associated with filedes doesn't support this call.
ENOTTY
The argument filedes doesn't refer to a terminal device.

Examples:

#include <termios.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>

int main( void )
  {
    int fd;

    fd = open( "/dev/ser1", O_RDWR );

    /* Disconnect for 500 milliseconds */
    tcdropline( fd, 500 );

    close( fd );
    return EXIT_SUCCESS;
  }

Classification:

QNX Neutrino

Safety:  
Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes