---
name: "statserial"
section: "1"
platform: "linux"
package: "statserial"
version: "1.1-25+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/statserial"
---

# statserial(1)

display serial port modem status lines

## NAME

statserial - display serial port modem status lines

## SYNOPSIS

statserial \[-n \|  -d \| -x\] \<device-name\>

## DESCRIPTION

**Statserial** displays a table of the signals on a standard 9-pin or 25-pin serial port, and indicates the status of the handshaking lines. It can be useful for debugging problems with serial ports or modems.

The optional **device-name** parameter is the full name of the device file for the serial port in question. If not specified, the default is taken from the  environment variable MODEM if set, otherwise /dev/ttyS0.

## COMMAND-LINE OPTIONS

Each of the command line options is mutually exclusive.

- **-n**

  Normally **statserial** will loop continuously, updating the status at one second intervals; you can exit using Control-C. The -n option disables looping.

- **-d**

  With this option the status of the modem is printed as a decimal number. The bits are encoded as follows (XXX indicates unused bits):

  \+---+---+---+---+---+---+---+---+---+\
   \| 8 \| 7 \| 6 \| 5 \| 4 \| 3 \| 2 \| 1 \| 0 \|\
   \+---+---+---+---+---+---+---+---+---+\
   \|DSR\|RI \|DCD\|CTS\|XXX\|XXX\|RTS\|DTR\|XXX\|\
   \+---+---+---+---+---+---+---+---+---+

- **-x**

  This option is the same as -d, except that the output is in hexadecimal.

## BUGS/LIMITATIONS

**Statserial** only works with devices that support the TIOCMGET ioctl.

You need permission to read the device file.

The device file may be locked if other applications are using it.

## AUTHOR

**Statserial** was written by Jeff Tranter (Jeff\_Tranter@Mitel.COM), later updated by  Frank Baumgart (godot@uni-paderborn.de) and is released under the  conditions of the GNU General Public License.  See the file COPYING and  notes in the source code for details.

## SEE ALSO

[setserial(8)](/setserial/8.md) [stty(1)](/stty/1.md)\
 /usr/src/linux/drivers/char/serial.c /usr/include/linux/termios.h