Hello All,

First of all, I just learn shell script and wondering how I can trap a
keyboard signal and exit out of the if loop as shown below:

myfile="/tmp/test"
if [ -f "$myfile" ]
then
cat $myfile
sleep 60
# if any key is hit before 60s, should end the if loop and go to next
command
fi
my_next_command_is_placed_here

Thanks a million,
Bob

Bob Bale <balebob@hotmail.com> wrote:
BB> Hello All,

BB> First of all, I just learn shell script and wondering how I can trap a
BB> keyboard signal and exit out of the if loop as shown below:

BB> myfile="/tmp/test"
BB> if [ -f "$myfile" ]
BB> then
BB> cat $myfile
BB> sleep 60
BB> # if any key is hit before 60s, should end the if loop and go to next
BB> command
BB> fi
BB> my_next_command_is_placed_here

This works. Just CTRL-C during the sleep.

#!/bin/ksh
trap : 2
sleep 60
echo $0

$ ./foo
../foo <- this is output after the CTRL-C

Regards,

Nicholas

--
http://www.faqs.org/rfcs/rfc1855.html
3.1.1 General Guidelines for mailing lists and NetNews
3.1.3 NetNews Guidelines

balebob@hotmail.com (Bob Bale) wrote in message news:<6385ed14.0403031542.2b8de33@posting.google.c om>...
> Hello All,
>
> First of all, I just learn shell script and wondering how I can trap a
> keyboard signal and exit out of the if loop as shown below:
>
> myfile="/tmp/test"
> if [ -f "$myfile" ]
> then
> cat $myfile
> sleep 60
> # if any key is hit before 60s, should end the if loop and go to next
> command
> fi
> my_next_command_is_placed_here
>
> Thanks a million,
> Bob

Check out the "trap" command, you can use this to trap signals i.e.
ctrl ^C, ctrl ^D (usually used to run a clean up function and
exit)... may not be what you are looking for ...

HTH
Mark Taylor

Thank you very much for all your suggestion.

I am thinking if I replace a cat command with a more command. Then I
can get out of the message any time I want. However, the system can
sit there for an hour if I am not press any key. Is there a way to do
like pausing for 60s if no key is hit then go to the next command,
instead of waiting for user to hit any key? It sounds simple, but I
do not know if it can be done or not.

Thanks,
Bob

Bob Bale <balebob@hotmail.com> wrote:
BB> Thank you very much for all your suggestion.

BB> I am thinking if I replace a cat command with a more command. Then I
BB> can get out of the message any time I want. However, the system can
BB> sit there for an hour if I am not press any key. Is there a way to do
BB> like pausing for 60s if no key is hit then go to the next command,
BB> instead of waiting for user to hit any key? It sounds simple, but I
BB> do not know if it can be done or not.

#!/bin/ksh
trap : 2

clear; ( less /etc/hosts & ); pid=$!

sleep 60
if ps -p $pid >/dev/null 2>&1
then
kill $pid
fi

stty sane
echo "\n$0"

Again, the user should be told that they have to press CTRL-C
to continue, if they want to preempt the 60-second sleep.

Regards,

Nicholas

--
http://www.faqs.org/rfcs/rfc1855.html
3.1.1 General Guidelines for mailing lists and NetNews
3.1.3 NetNews Guidelines

Thank you very much, Nicholas. It works like a charm...Is there a way
to trap a "spacebar" key stroke signal instead of asking user to hold
down Ctrl and hit C?

Thanks,
Bob.

Nicholas Dronen <ndronen@io.frii.com> wrote in message news:<4047da80$0$200$75868355@news.frii.net>...
> Bob Bale <balebob@hotmail.com> wrote:
> BB> Thank you very much for all your suggestion.
>
> BB> I am thinking if I replace a cat command with a more command. Then I
> BB> can get out of the message any time I want. However, the system can
> BB> sit there for an hour if I am not press any key. Is there a way to do
> BB> like pausing for 60s if no key is hit then go to the next command,
> BB> instead of waiting for user to hit any key? It sounds simple, but I
> BB> do not know if it can be done or not.
>
> #!/bin/ksh
> trap : 2
>
> clear; ( less /etc/hosts & ); pid=$!
>
> sleep 60
> if ps -p $pid >/dev/null 2>&1
> then
> kill $pid
> fi
>
> stty sane
> echo "\n$0"
>
> Again, the user should be told that they have to press CTRL-C
> to continue, if they want to preempt the 60-second sleep.
>
> Regards,
>
> Nicholas