How to time out a program in bash

[Steve Flynn]

On Tue, Oct 6, 2009 at 6:22 PM, Kevin O'Gorman <kogorman at gmail.com> wrote:
> I'm not sure where to ask this, but surely there are bash script experts
> watching...
>
> I'm trying to write a bash script to test a some student programs.  Some of
> them
> get wedged, and I can use ulimit to catch most of that.  However, if they
> wedge
> reading stdin when they are not supposed to, ulimit does not catch them.
>
> Can a bash script use an alarm?  Anybody have a quick recipe?  Or another
> approach?

If the $TMOUT environmental variable is set to a non-zero value time,
then the shell prompt will
time out after $time seconds. This will cause a logout.

If you can persuade the students to use some supplied code:

TIMELIMIT=4                     # 4 seconds
read -t $TIMELIMIT variable <&1
#
# In this instance, "<&1" is needed for Bash 1.x and 2.x,
# but unnecessary for Bash 3.x.


-- 
Steve
When one person suffers from a delusion it is insanity. When many
people suffer from a delusion it is called religion.

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