Review your favorite Linux distribution.
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 02-21-2009, 10:48 PM   #1
Registered: Feb 2007
Location: TX, USA
Distribution: fedora
Posts: 191

Rep: Reputation: 33
Thumbs up Sighup

Hi can anybody say about SIGHUP signal. I read its for hangup but i didnot understand whats meant by that. Pls tell me in very simple sense. Pls don't refer me to any website. I want our knowledge because its easier to learn from u than from website. Thanks.
Old 02-21-2009, 11:16 PM   #2
Registered: Sep 2007
Location: Las Vegas, NV
Distribution: Fedora / CentOS
Posts: 674
Blog Entries: 3

Rep: Reputation: 90
it's a method for the OS and other programs to send specific signals between each other. SIGHUP is basically like a "I'm asking you nicely to quit" message.

Here's some other examples of Linux Signals:
Old 02-22-2009, 05:36 AM   #3
Senior Member
Registered: Dec 2007
Location: Croatia
Distribution: Debian GNU/Linux
Posts: 1,733
Blog Entries: 5

Rep: Reputation: 127Reputation: 127
There's something interesting if you would like to know;SIGHUP can be intercepted and handled,like all SIG signals except SIGKILL and SIGSTOP.
Old 02-22-2009, 06:08 AM   #4
LQ Guru
Registered: Aug 2004
Location: Sydney
Distribution: Centos 6.10, Centos 7.3
Posts: 17,524

Rep: Reputation: 2417Reputation: 2417Reputation: 2417Reputation: 2417Reputation: 2417Reputation: 2417Reputation: 2417Reputation: 2417Reputation: 2417Reputation: 2417Reputation: 2417
It originally dates from the old days, when everything was dial-up (eg ARPANet, precursor to internet).
It literally means hang-up the phone line, which is why you use

nohup prog

to ensure a prog keeps running when you logout, otherwise it dies, because its still attached to the terminal session, even if you use '&'. '&' only puts it in the background, its still connected to your term session.
These days SIGHUP is in fact usually used to get a prog eg Apache to re-read its config file on the fly ie without an explicit re-start.



Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
SIGHUP / kill -1 SlowCoder Linux - General 6 01-30-2008 06:38 PM
Sending SIGHUP to inetd glansing Linux - Newbie 3 09-16-2005 02:13 AM
How inetd gets sighup? rajesh_b Programming 1 09-17-2004 04:38 AM > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 12:47 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration