Oh! The ruby analogy made me think about actually spawning the detached
command! Which produced the desired effect!
julia> @spawn run(detach(`ping www.google.com`))
vineri, 22 ianuarie 2016, 22:29:27 UTC+1, Adrian Salceanu a scris:
>
> I guess what I'm looking for is the equivalent of Ruby's Process#spawn
>
> In REPL:
>
> >> pid = Process.spawn("ping www.google.com", :out => '/dev/null')
> 83210
> >> <-- the process is running in the background
> and control has been returned to the REPL
>
>
> vineri, 22 ianuarie 2016, 22:06:01 UTC+1, Adrian Salceanu a scris:
>>
>> Hi,
>>
>> I'm hammering at a web app and I'm trying to setup functionality to
>> monitor the file system for changes and restart/reload the server
>> automatically so the changes are picked up (I'm using Mux which uses
>> HttpServer).
>>
>> The approach I have in mind is:
>>
>> 1. have a startup script which is run from the command line, something
>> like:
>> $ julia -L startup.jl
>>
>> 2. the startup script launches the web app, which starts the web server.
>> My intention was to run
>> $ julia -L app.jl
>> as a command inside startup.jl, detached, and have the startup.jl script
>> get back control, with app.jl running detached in the background.
>>
>> 3. once startup.jl gets back control, it begins monitoring the file
>> system and when changes are detected, kills the app and relaunches it.
>>
>> That was the theory. Now, I might be missing something but I can't find a
>> way to detach the command I'm running and get control back to the startup
>> script. And I tried a lot of things!
>>
>> ===
>>
>> I'm providing simpler example using "ping", which also run indefinitely,
>> similar to the web server.
>>
>> julia> run(detach(`ping "www.google.com"`)) # the command is detached
>> and continues to run after the julia REPL is closed, but at this point the
>> REPL does not get control, there's no cursor available in the REPL
>> PING www.google.com (173.194.45.82): 56 data bytes
>> 64 bytes from 173.194.45.82: icmp_seq=0 ttl=54 time=30.138 ms
>> 64 bytes from 173.194.45.82: icmp_seq=1 ttl=54 time=30.417 ms
>> ... more output ...
>> 64 bytes from 173.194.45.82: icmp_seq=7 ttl=54 time=30.486 ms
>> 64 bytes from 173.194.45.82: icmp_seq=8 ttl=54 time=30.173 ms
>> ^CERROR: InterruptException:
>> <---- here I press Ctrl+C and only now the REPL gets
>> back the cursor, with the command still running in the background
>>
>> ===
>>
>> Also, related to this, passing "&" into the command to detach does not
>> work as expected, the "&" is interpreted as argument of the command. Not
>> sure if this would help anyway to return control to the startup.jl script?
>>
>> julia> run(detach(`ping "www.google.com" &`));
>> usage: ping [-AaDdfnoQqRrv] [-b boundif] [-c count] [-G sweepmaxsize]
>> [-g sweepminsize] [-h sweepincrsize] [-i wait] [−k
>> trafficclass]
>> [-l preload] [-M mask | time] [-m ttl] [-p pattern]
>> [-S src_addr] [-s packetsize] [-t timeout][-W waittime] [-z
>> tos]
>> host
>> ping [-AaDdfLnoQqRrv] [-b boundif] [-c count] [-I iface] [-i wait]
>> [−k trafficclass] [-l preload] [-M mask | time] [-m ttl] [-p
>> pattern] [-S src_addr]
>> [-s packetsize] [-T ttl] [-t timeout] [-W waittime]
>> [-z tos] mcast-group
>> ERROR: failed process: Process(`ping www.google.com &`,
>> ProcessExited(64)) [64]
>> in run at /usr/local/Cellar/julia/0.4.2/lib/julia/sys.dylib
>>
>> ===
>>
>> Thanks
>>
>
