Okay, sleep is ran in a child process. That makes sense, but when I press CTRL c for the child process, why does the child process not echo the message to the screen?
Isn't the trap modification getting sent to the child process as well or does this modification only get applied to the parent process?
Is there a way to run sleep in the parent shell and not a child shell, so my trap modification will work?
I am not familiar with
Is it pretty much the same as sleep, except in nano-seconds instead of seconds?
you said that it sets up a signal handler for SIGALRM. If I add in SIGALRM into the trap command will this resolve the issue? ex:
Then again, will this just get applied to the parent shell and not the child shell?
Please be thorough in your response, so I can understand what's going on. Thanks
hi!!,
i wanna trap all Signal 10, 11, 15 generated by any process running on my server irrespective of the user and wanna write to a log file. Any ideas? Do this script need to be a root process??
:cool: (1 Reply)
Hello all,
I'm hoping to get a little insight from some of the wily veterans amongst you.
I've written a script to check for new outgoing files to our vendors located on our ssl server. It seems to be working ok, but the final question here, will be one of logic, and/or a better way to... (4 Replies)
Hi folks,
I have tried to add some trap detection in the below script....this script is used to monitor database activities...in a rather awkward way :rolleyes:....
The idea behind adding trap is that....this script creates lots of temporary files in the running folder to store the count... (1 Reply)
(posted this in the scripting forum as well, but figured it should go here) So, what's going on is this:
For our program, we had to create our own shell, and if the user pressed ctrl-c just at the cmdline, then this signal would be ignored, but if there is a foreground process running, let's... (0 Replies)
How can use signals in a C program If i want a child program to signal it's parent program that it(child) program has completed the task that it was assigned.:confused: (2 Replies)
Hi all,
I have the c program that c program has to be in sleep mode.
I want write a script the it should trap the signal from the c program.
The signals are sighup,sigkill,sigterm,sigchld and then it has to go to sleep.
If signal is sigchld it has to do to some function.
My question is how to... (3 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
That is the last reply I received from my instructor, and I'm looking for some alternatives.
When using... (2 Replies)
Hi All,
The problem statement is as below:
Problem: A process (exe) is getting executed in background. The output of this process is getting logged in a file. After successfully running for some time the process gets terminated. In the log file following is present:
^M[7m Interrupt ^M[27m... (8 Replies)
let LIMIT=50
function check {
if ]; then
print LIMIT OK
else
print "LIMIT changed!"
fi
}
trap check DEBUG
print $LIMIT
LIMIT=$((LIMIT + 30))
trap - DEBUG
Can anyone tell me how debugging is accomplished?? (4 Replies)
Discussion started by: Karthick N
4 Replies
LEARN ABOUT NETBSD
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)