Provided by: util-linux_2.34-0.1ubuntu2_amd64 bug


       ldattach - attach a line discipline to a serial line


       ldattach [-1278denoVh] [-i iflag] [-s speed] ldisc device


       The  ldattach  daemon  opens  the  specified  device  file (which should refer to a serial
       device) and attaches the line discipline ldisc to it for processing  of  the  sent  and/or
       received  data.  It then goes into the background keeping the device open so that the line
       discipline stays loaded.

       The line discipline ldisc may be specified either by name or by number.

       In order to detach the line discipline, kill(1) the ldattach process.

       With no arguments, ldattach prints usage information.


       Depending on the kernel release, the following line disciplines are supported:

       TTY(0) The default line discipline, providing transparent operation (raw mode) as well  as
              the habitual terminal line editing capabilities (cooked mode).

              Serial  Line  IP  (SLIP)  protocol  processor  for transmitting TCP/IP packets over
              serial lines.

              Device driver for RS232 connected pointing devices (serial mice).

       PPP(3) Point to Point Protocol (PPP)  processor  for  transmitting  network  packets  over
              serial lines.



       X25(6) Line driver for transmitting X.25 packets over asynchronous serial lines.


              Driver for Simatic R3964 module.

              Linux IrDa (infrared data transmission) driver - see

              Synchronous HDLC driver.

              Synchronous PPP driver.

              Bluetooth HCI UART driver.

              Driver for Siemens Gigaset M101 serial DECT adapter.

              Driver for serial line Pulse Per Second (PPS) source.

              Driver for GSM 07.10 multiplexing protocol modem (CMUX).


       -1, --onestopbit
              Set the number of stop bits of the serial line to one.

       -2, --twostopbits
              Set the number of stop bits of the serial line to two.

       -7, --sevenbits
              Set the character size of the serial line to 7 bits.

       -8, --eightbits
              Set the character size of the serial line to 8 bits.

       -d, --debug
              Keep  ldattach  in the foreground so that it can be interrupted or debugged, and to
              print verbose messages about its progress to standard error output.

       -e, --evenparity
              Set the parity of the serial line to even.

       -i, --iflag [-]value...
              Set the specified bits in the c_iflag word of the serial line.  The given value may
              be  a  number  or  a  symbolic  name.   If  value  is prefixed by a minus sign, the
              specified bits are cleared instead.  Several comma-separated values may be given in
              order to set and clear multiple bits.

       -n, --noparity
              Set the parity of the serial line to none.

       -o, --oddparity
              Set the parity of the serial line to odd.

       -s, --speed value
              Set the speed (the baud rate) of the serial line to the specified value.

       -c, --intro-command string
              Define  an intro command that is sent through the serial line before the invocation
              of ldattach.  E.g.  in  conjunction  with  line  discipline  GSM0710,  the  command
              ´AT+CMUX=0\r´ is commonly suitable to switch the modem into the CMUX mode.

       -p, --pause value
              Sleep for value seconds before the invocation of ldattach. Default is one second.

       -V, --version
              Display version information and exit.

       -h, --help
              Display help text and exit.


       inputattach(1), ttys(4)


       Tilman Schmidt (


       The   ldattach   command  is  part  of  the  util-linux  package  and  is  available  from