@spawn runs a command on a (random) worker process. If you want to do "background" work in the current process, you can use @async:
julia> t = @async (sleep(5); rand()) Task (runnable) @0x0000000112d746a0 julia> wait(t) 0.14543742643271207 On Fri, Jan 22, 2016 at 4:33 PM, Adrian Salceanu <[email protected]> wrote: > 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 >>> >>
