# Setting Timeout and C-C capture

**URL:** <https://discourse.julialang.org/t/setting-timeout-and-c-c-capture/15487>\
**Category:** New to Julia\
**Tags:** interruptexception\
**Created:** [September 25, 2018, 9:19pm UTC](https://discourse.julialang.org/t/setting-timeout-and-c-c-capture/15487 "2018-09-25T21:19:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![iwelch](https://avatars.discourse-cdn.com/v4/letter/i/8c91f0/32.png) [@iwelch](https://discourse.julialang.org/u/iwelch)\
**Post date:** [September 25, 2018, 9:19pm UTC](https://discourse.julialang.org/t/setting-timeout-and-c-c-capture/15487/1 "2018-09-25T21:19:04Z")

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dear Julia wizards—I want to create julia code segments that recognize (and trap) a control-C; and I want to create julia code that times out. my julia code segments may be trying to obtain something from the host computer or from the network.

### Trapping C-C

```julia-auto
julia> ## enable trapping of ^C. ccall( :jl_exit_on_sigint, Nothing, (Cint,), 0 ) fails

julia> try
	    ticks= 0
	    while true
	        sleep(0.5)
	        ticks += 1
	        println( "Please type ^C now ($ticks)" )
	    end##while##
       finally
	    println("OK, we are breaking out!")
       end##try##

julia> println("Freedom!")	## is not reached, because ^C stops execution after try

julia> ## restore standard ^C behavior

```

### Setting Timeout

I know how to do this in perl, but not in Julia. In perl

```julia-auto
   eval {
        local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n required
        alarm $timeout;
        my $nread = sysread $socket, $buffer, $size;	## an example of a function where we do not know if it will work
        alarm 0;
    };
    if ($@) {
        die unless $@ eq "alarm\n"; # propagate unexpected errors
        # timed out
    }
    else {
        # didn't
    }

```

Does anyone have working examples?

regards,

/iaw

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<div class="post-metadata">

**Author:** ![ssfrr](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ssfrr/32/3736_2.png) [@ssfrr](https://discourse.julialang.org/u/ssfrr)\
**Post date:** [September 26, 2018, 3:51pm UTC](https://discourse.julialang.org/t/setting-timeout-and-c-c-capture/15487/2 "2018-09-26T15:51:58Z")

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In Julia ctrl-C throws an `InterruptException`, so you should just be able to do something like

```julia
try
    # code that might take a while, e.g.
    sleep(10)
catch ex
    if ex isa InterruptException
        println("we got interrupted")
    else
        rethrow()
    end
end

```

That said, I just tested this on my Windows box and it actually waits until the `sleep` call completes before throwing the exception, which is weird.

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<div class="post-metadata">

**Author:** ![iwelch](https://avatars.discourse-cdn.com/v4/letter/i/8c91f0/32.png) [@iwelch](https://discourse.julialang.org/u/iwelch)\
**Post date:** [September 26, 2018, 4:17pm UTC](https://discourse.julialang.org/t/setting-timeout-and-c-c-capture/15487/3 "2018-09-26T16:17:12Z")

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thanks, ssfr. on macos, this code works! now all I need is the alarm/timeout ;-).