winget install --id=SpectrumIntegrators.Sercat -e sercat is a command-line serial terminal in the spirit of netcat: everything is set on the command line, and the terminal sends what you type and prints what's received. It supports configurable display of nonprintable bytes (raw, dots, escaped, or full hex), sending files with optional escape parsing and pacing, and clean piping to and from stdin/stdout.
netcat for serial ports. Everything is set on the command line; the terminal sends what you type and shows what's received. No GUI, no terminal-library magic — just stdin and stdout, so it pipes cleanly.
sercat COM3 -b 115200
Framework-dependent .NET 8 app — needs the .NET 8 runtime installed (the desktop runtime that ships with most Windows dev setups is fine).
dotnet build -c Release # -> bin\Release\net8.0\sercat.exe
# or, to stage a publish folder:
dotnet publish -c Release # -> bin\Release\net8.0\publish\sercat.exe
Dependencies: CommandLineParser
(argument parsing) and System.IO.Ports
(serial access), both restored automatically.
sercat [options] PORT
sercat --list-ports
| Option | Default | Notes |
|---|---|---|
PORT | — | e.g. COM3 (required unless --list-ports) |
-b, --baud N | 9600 | |
--data-bits N | 8 | 5–8 |
--parity P | none | none|even|odd|mark|space |
--stop-bits N | 1 | 1|1.5|2 |
--flow F | none | none|xonxoff|rtscts |
--dtr on|off | on | opening a port toggles DTR — --dtr off avoids resetting Arduinos |
--rts on|off | on |
| Option | Default | Notes |
|---|---|---|
-m, --mode M | print | print|dots|escaped|hex |
--printable RANGE | 0x20-0x7E | e.g. 0x20-0x7E or 32-126 |
--force-mode | off | apply --mode even when stdout is a pipe |
..\xNN.\xNN regardless of printability.| Option | Default | Notes |
|---|---|---|
--send-file PATH | — | escapes parsed by default |
--raw | off | with --send-file: send verbatim bytes, no parsing |
-q, --quit | off | exit after the file (or piped stdin) is sent |
--append-newline E | none | append cr|lf|crlf|none to each typed line |
--tx-delay MS | 0 | delay between lines/chunks when sending (paces slow devices) |
--no-parse | off | don't parse \xNN escapes on interactive input |
-l, --list-ports · -h, --help · --version
Interactive keyboard input is line-buffered (cooked mode): the OS handles echo, backspace, and paste, and hands sercat a whole line when you press Enter. That line is parsed for escapes and sent. This makes it easy to paste a value out of a manual.
Escape vocabulary (used for typed input and for --send-file parsing):
\xNN one byte from two hex digits \\ a literal backslash
\n \r \t \0 \a \b \f \v the usual C control bytes
The Enter that submits a line is not sent. To send a line ending, write it explicitly
(\x0D, \x0A) or use --append-newline. An invalid escape prints an error and the line
is not sent, so you can retype it.
> AT\x0D sends: 41 54 0D
> \x02payload\x03 sends: 02 ... 03
type data.bin | sercat COM3) is forwarded as raw bytes — no escape
parsing, no line buffering — so binary data passes through untouched.sercat COM3 -m hex > log.txt) defaults to raw bytes for binary
safety, ignoring --mode unless you pass --force-mode.0x1A
end-of-file corruption.type firmware.bin | sercat COM3 -b 115200 -q # send a file and exit
sercat COM3 > capture.bin # capture raw received bytes
sercat --list-ports
sercat COM3 -b 115200 # interactive, raw display
sercat COM3 -m escaped # show control bytes as \xNN
sercat COM3 -m hex # hex-dump every received byte
sercat COM4 --send-file commands.txt --tx-delay 50 # send a script, pacing slow device
sercat COM4 --send-file image.bin --raw -q # send a binary file verbatim, then quit
Press Ctrl+C to quit (the port is released cleanly). To send a literal control byte by
hand, type its escape, e.g. \x03 for Ctrl+C.
dots/escaped/hex modes — by design.System.IO.Ports; primary target is Windows.