Can you tell us what exactly you are trying to do?
If you are trying to instruct a script to handle certain task while it is already running, then you can use trap to catch a user-defined signal and perform an action.
For example, here is a script:
If you run this script on a session and from another session if you send a USR1 signal to the running script PID, the trap argument will be executed:
Modify it as per your requirement. I hope this helps.
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)
Hello
I have a master startup script (let's call it myScript) that displays a menu from which the user can start/stop several instances of a server. When I issue the start command for one of the servers from the menu and then exit myScript through the provided mechanism (enter "q" in this case),... (2 Replies)
Greetings,
I am writing an Expect script to automate multiple processes on an HP-UX system. Everything has gone fine so far but I now have run into a problem. One of the processes that I'm trying to automate requires the key combination of ctrl break and I have so far been unable to figure out... (1 Reply)
I'm trying to do a program that makes activate an signal (SINGALARM) when the next child of a son appears but this not works.
I have to caught the next child o the other (pid), to send a singnal which inform a menssage.
It's anything worng in the code?
thanks.
the code:
#include... (2 Replies)
Hi i want to know how can i write a script to check if any changes are made and send an alert in crontabs . i am using .ksh file extension for writing scripts. (3 Replies)
im trying to make a trap signal 2 (ctrl c) in a bash script
if a user presses ctrl c while running the script it should display an error message but not quit the bash script just yet. User will have to press "enter" to quit
This is what i have so far
#trap trap_control 2
#while true
#do... (6 Replies)
Hi,
Am trying to transfer file via FTP using expect script from server to client
i need to interrupt the file transfer between server and client
Please help what should used in expect code..
I used
send "ctrl+c\r"
expect "Aborted"
but that didnt work.. I need what should... (3 Replies)
Hey All,
I am writing one script using expect, that script which is used in spawn will accepts only 1. Enter 2. Ctrl+c
Press Control-C to exit, Enter to proceed.
Could some one share some thoughts to send the above user inputs in linux expect block ?
Thanks,
Sam (0 Replies)
Discussion started by: SCHITIMA
0 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)