Sending control codes to the console in C / Computer Science / Forums

Welcome

Online

Members Birthdays:

One birthday today, congrats!
Vaxian (17)

Next birthdays
05/21 Dalus (34)
05/21 Kizmo (37)
05/22 Skynet (32)

Contact

Support 4hv.org!

Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:

Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis

The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.

Forums

4hv.org :: Forums :: Computer Science

« Previous topic | Next topic »

Sending control codes to the console in C

Move Thread

LAN_403

scrooch

Sat Mar 28 2009, 12:30PM

Registered Member #908 Joined: Wed Jul 18 2007, 05:53AM
Location:
Posts: 49

hi how do i send control codes such as "Enter", "Esc","ctrl+z" etc etc from C to the linux shell?

Steve Conner

Sat Mar 28 2009, 07:22PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

You can usually escape them, though the exact syntax for escaping depends on how you're feeding stuff to the shell.

If you were using sprintf() to stuff command lines through a pipe, or something, then you can escape things in C string constants with a backslash. There are letters for common ones, for instance \n is a newline, or you can type the ASCII code you want after the backslash (in octal mind you!)

Also C lets you append hex constants sometimes. For instance

sprintf(buffer, "rm -f -r *\n") // \n adds a newline

char MyCommand[20];
MyCommand={"Whee", 0x0d, 0x0a}; // Whee, CR, LF

and so on.

I guess if you want to escape an escape, the ASCII code for ESC is 0x13.
Finally bear in mind not all systems are ASCII any more, some use Unicode.

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob

Legal Information