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Old 10-19-2003, 07:20 AM   #1
AMMullan
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Registered: Sep 2003
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trap signals


I am trying to put some trap signals in a bash script i am working on but i'm not sure how to use it.

Has anyone got any ideas or examples?
 
Old 10-19-2003, 10:03 AM   #2
Hko
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Run this script. Hit CTRL-C 6 times, and see what happens, and how it works.
Code:
#!/bin/sh

count=0

# Declare function to handle CTRL-C signals
signal_func() {
    count=$((count + 1))
    echo "INT signal received $count times."
    if [ $count -ge 5 ] ; then  # After 5 INT's 
	# reset signal handling to  default.
	trap - INT
    fi
}

# Install handler for INT signals (CTRL-C)
trap 'signal_func' INT

# Loop doing nothing for demo.
while true ; do
    sleep 1000000
    echo "Woken up"
done

# we never get here.
exit 0
 
Old 10-19-2003, 02:17 PM   #3
AMMullan
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Thats primo

Is there also a way that if they wanted to press Q that it could break the script aswell?
 
Old 10-19-2003, 05:31 PM   #4
Hko
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To do that, you would need to run a program in the background that signals the shell executing the script when Q is pressed. I don't know if such a program exists, but it shouldn't be to difficult to make (in C or C++).
 
  


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