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 PHP
trap
trap(1) User Commands trap(1)NAME
trap, onintr - shell built-in functions to respond to (hardware) signals
SYNOPSIS
sh
trap [ argument n [n2...]]
csh
onintr [-| label]
ksh
*trap [ arg sig [ sig2...]]
DESCRIPTION
sh
The trap command argument is to be read and executed when the shell receives numeric or symbolic signal(s) (n). (Note: argument is scanned
once when the trap is set and once when the trap is taken.) Trap commands are executed in order of signal number or corresponding symbolic
names. Any attempt to set a trap on a signal that was ignored on entry to the current shell is ineffective. An attempt to trap on signal 11
(memory fault) produces an error. If argument is absent all trap(s) n are reset to their original values. If argument is the null string
this signal is ignored by the shell and by the commands it invokes. If n is 0 the command argument is executed on exit from the shell. The
trap command with no arguments prints a list of commands associated with each signal number.
csh
onintr controls the action of the shell on interrupts. With no arguments, onintr restores the default action of the shell on interrupts.
(The shell terminates shell scripts and returns to the terminal command input level). With the - argument, the shell ignores all inter-
rupts. With a label argument, the shell executes a goto label when an interrupt is received or a child process terminates because it was
interrupted.
ksh
trap uses arg as a command to be read and executed when the shell receives signal(s) sig. (Note that arg is scanned once when the trap is
set and once when the trap is taken.) Each sig can be given as a number or as the name of the signal. trap commands are executed in order
of signal number. Any attempt to set a trap on a signal that was ignored on entry to the current shell is ineffective. If arg is omitted
or is -, then the trap(s) for each sig are reset to their original values. If arg is the null (the empty string, e.g., "" ) string then
this signal is ignored by the shell and by the commands it invokes. If sig is ERR then arg will be executed whenever a command has a non-
zero exit status. If sig is DEBUG then arg will be executed after each command. If sig is 0 or EXIT for a trap set outside any function
then the command arg is executed on exit from the shell. The trap command with no arguments prints a list of commands associated with each
signal number.
On this man page, ksh(1) commands that are preceded by one or two * (asterisks) are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of a variable assignment, are expanded with the same rules as a vari-
able assignment. This means that tilde substitution is performed after the = sign and word splitting and file name generation are not
performed.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO csh(1), exit(1), ksh(1), sh(1), attributes(5)SunOS 5.10 23 Oct 1994 trap(1)