Trapping signal from shell script... doesn't seem to work?

Dan Nelson dnelson at
Wed Feb 7 16:46:36 UTC 2007

In the last episode (Feb 07), Aitor San Juan said:
> I have written a Bourne shell script. This shell script invokes a
> program written in the C language.
> Below is basically the shell script source code. As you can see, the
> C program is not invoked in the background, but in the foreground, so
> the shell script doesn't finish until the C program has finished.
> I want the shell script to trap TERM or INT signals, so when any of
> these are raised, the shell script will try to send SIGTERM to the
> program "myprog":

Since you didn't background "myprog", the shell can't do anything until
it returns, including signal processing.  See the text at

There's a nice page about trap handling and shells at

, which includes an example that does what you want:

 #! /bin/sh
     kill $pid

 trap onint SIGINT
 ./hardguy &
 wait $pid

	Dan Nelson
	dnelson at

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