Well, signals go to all the processes, so the trap is in the tail's parent. You could open a subshell and set the trap just in there. It it is in a script, on most UNIX it is in a script-running subshell of the login shell. So, if you want the trap message to go up the pipe from the controlling shell, you probably need something like this:
Also, Ctrl-C is SIGINT not SIGERR(?), see man kill:
I wrote a ksh script for Helpdesk. I need to know how to disable ctrl-c,ctrl-z,ctrl-d..... so that helpdesk would not be able to get to system prompt :confused: (6 Replies)
how to trap the ctrl c in unix shell script
my script is running in while loop it should not be terminate with ctrl c.
if i press ctrl c while running script it shloud ignore the same.
please healp..........
thanks in advance (2 Replies)
Hello at my home when i try
tail +5 emp
it works but when i try in my college it doesn't work! what can be the problem any idea?
when i type
man tail
it gives me various options in which it's mentioned that tail +n can also work when you want to display from nth line. But... (3 Replies)
I've search the various posts in these forums, but have not come up with a solution to my problem.
I have a parent process that calls a child script, runs it in the background and the parent finishes - without waiting for the child process to complete. Inside the child, a trap is issued to trap... (6 Replies)
I am trying to trap CTRL-C, now the program I call has it's own exit message, I think this is the problem ..
This is what I have now :
function dothis
{
echo 'you hit control-c'
exit
}
function settrap
{
trap dothis SIGINT
}
settrap
until false; do
./ITGRecv.exe
doneDoing this I... (2 Replies)
Hello,
I have a script which copies via scp several large files to a remote server. What I want is that even if someone hits CTRL-C, the scp commands continues till the end.
Here is what I wrote
#! /bin/bash
function testFunction
{
echo "COPY START"
scp large.tar.gz... (11 Replies)
say i have a statement like this in a script
tail -f /opt/blah/blha/user.log > final.log
if ;then
cat final.log | grep -i "servicer_user" > service.log
cat final.log | grep -i "logic_user" > logic.log
fi
echo "script completed"
but when the script is running if i press ctrl + c the... (4 Replies)
Hi All,
I have ran one command tail -f <filename> to view newly appended text to that file. When i was done i pressed ctrl+c command to stop it but to my suprise it didn't work. I then tried top command and pressed ctrl+c and it worked fine and command aborted.
I then just checked the tail... (0 Replies)
Hi Folks -
For some reason, my trap command is not working. It's placed just prior to a normal exit:
#:: ------------------------------------------------------------------------
#::-- Script Name: LCM_Backup.sh
#::
#::-- Description: This script leverages Utility.sh to perform LCM... (16 Replies)
Hello:
Am trying to understand why the method #2 works but method #1 does not.
For both methods, sending CTRL+C should kill both the Parent script & all of the spanwd background procs.
Method #1:
==========================
#!/bin/sh
ctrl_c()
{
echo "** Trapped CTRL-C"
... (3 Replies)
Discussion started by: gilgamesh
3 Replies
LEARN ABOUT CENTOS
sigtrap
sigtrap(3pm) Perl Programmers Reference Guide sigtrap(3pm)NAME
sigtrap - Perl pragma to enable simple signal handling
SYNOPSIS
use sigtrap;
use sigtrap qw(stack-trace old-interface-signals); # equivalent
use sigtrap qw(BUS SEGV PIPE ABRT);
use sigtrap qw(die INT QUIT);
use sigtrap qw(die normal-signals);
use sigtrap qw(die untrapped normal-signals);
use sigtrap qw(die untrapped normal-signals
stack-trace any error-signals);
use sigtrap 'handler' => &my_handler, 'normal-signals';
use sigtrap qw(handler my_handler normal-signals
stack-trace error-signals);
DESCRIPTION
The sigtrap pragma is a simple interface to installing signal handlers. You can have it install one of two handlers supplied by sigtrap
itself (one which provides a Perl stack trace and one which simply "die()"s), or alternately you can supply your own handler for it to
install. It can be told only to install a handler for signals which are either untrapped or ignored. It has a couple of lists of signals
to trap, plus you can supply your own list of signals.
The arguments passed to the "use" statement which invokes sigtrap are processed in order. When a signal name or the name of one of
sigtrap's signal lists is encountered a handler is immediately installed, when an option is encountered it affects subsequently installed
handlers.
OPTIONS
SIGNAL HANDLERS
These options affect which handler will be used for subsequently installed signals.
stack-trace
The handler used for subsequently installed signals outputs a Perl stack trace to STDERR and then tries to dump core. This is the
default signal handler.
die The handler used for subsequently installed signals calls "die" (actually "croak") with a message indicating which signal was caught.
handler your-handler
your-handler will be used as the handler for subsequently installed signals. your-handler can be any value which is valid as an
assignment to an element of %SIG. See perlvar for examples of handler functions.
SIGNAL LISTS
sigtrap has a few built-in lists of signals to trap. They are:
normal-signals
These are the signals which a program might normally expect to encounter and which by default cause it to terminate. They are HUP,
INT, PIPE and TERM.
error-signals
These signals usually indicate a serious problem with the Perl interpreter or with your script. They are ABRT, BUS, EMT, FPE, ILL,
QUIT, SEGV, SYS and TRAP.
old-interface-signals
These are the signals which were trapped by default by the old sigtrap interface, they are ABRT, BUS, EMT, FPE, ILL, PIPE, QUIT, SEGV,
SYS, TERM, and TRAP. If no signals or signals lists are passed to sigtrap, this list is used.
For each of these three lists, the collection of signals set to be trapped is checked before trapping; if your architecture does not
implement a particular signal, it will not be trapped but rather silently ignored.
OTHER
untrapped
This token tells sigtrap to install handlers only for subsequently listed signals which aren't already trapped or ignored.
any This token tells sigtrap to install handlers for all subsequently listed signals. This is the default behavior.
signal
Any argument which looks like a signal name (that is, "/^[A-Z][A-Z0-9]*$/") indicates that sigtrap should install a handler for that
name.
number
Require that at least version number of sigtrap is being used.
EXAMPLES
Provide a stack trace for the old-interface-signals:
use sigtrap;
Ditto:
use sigtrap qw(stack-trace old-interface-signals);
Provide a stack trace on the 4 listed signals only:
use sigtrap qw(BUS SEGV PIPE ABRT);
Die on INT or QUIT:
use sigtrap qw(die INT QUIT);
Die on HUP, INT, PIPE or TERM:
use sigtrap qw(die normal-signals);
Die on HUP, INT, PIPE or TERM, except don't change the behavior for signals which are already trapped or ignored:
use sigtrap qw(die untrapped normal-signals);
Die on receipt one of an of the normal-signals which is currently untrapped, provide a stack trace on receipt of any of the error-signals:
use sigtrap qw(die untrapped normal-signals
stack-trace any error-signals);
Install my_handler() as the handler for the normal-signals:
use sigtrap 'handler', &my_handler, 'normal-signals';
Install my_handler() as the handler for the normal-signals, provide a Perl stack trace on receipt of one of the error-signals:
use sigtrap qw(handler my_handler normal-signals
stack-trace error-signals);
perl v5.16.3 2013-03-04 sigtrap(3pm)