21.07.2014 19:14, tantalum пишет: >> Are there some code examples? > except for process-chain-* probably not, but i put that on my todo list. > > something like this should work: > (execute-with-environment "XX2=LOL" "/tmp/mybin") > > working example: > guile -c '(import (sph process)) (execute-with-environment (list > "XX2=LOL") "/usr/bin/echo" "test")' > > but this is using the system call "execve", which leads to the whole > guile process being replaced by the specified program. (execve syscall > reference: http://man7.org/linux/man-pages/man2/execve.2.html)
Neat. Just to double-check - the environment variables of my current process are preserved or /tmp/mybin would run with environment consisting only of variables which I've explicitly put into execute-with-environment? > > "process-create" creates a new parallel process > --- > (define pid > (process-create > (lambda () > ;this will be executed in a completely cloned new process in the > background > (execute-with-environment "XX2=LOL" "/tmp/mybin")))) > > ;now, still in the guile process, send a signal to the new process > (kill pid SIGINT) > --- > now what happens is that a new process is created by cloning, and is > then immediately replaced by your program. as far as i know this is the > only way on linux or similar systems to archieve this. Yes, that's totally fine. > > for storing values in a record it would probably be best to use a record > setter procedure. the library supports setting fields by symbolic name, > but that is slower. Could you illustrate that with some code too? I do not plan to have that many records so I'm not concerned with the speed that much :) > in general, as a sidenote, a record like this differs from an > association list for example, in that the keys are not stored inside the > data-structure, but separately: the "layout" stores the field names and > the positions of where the field values are stored in the records. > example: > --- > (define myrec (make-record-layout (quote (pid env)))) > (define-record-accessors myrec (myrec-pid (quote pid)) (myrec-env (quote > env))) > (define-record-setters myrec (myrec-pid-set! (quote pid)) > (myrec-env-set! (quote env))) Hmm... looks like a boilerplate - I thought those are generated automatically. > ;two different ways to create a record > (define a (record myrec pid "LOL")) > (define b (make-record myrec)) > > (myrec-pid a) > (myrec-pid-set! a 3) > (myrec-env-set! b 2) > --- I can also have arbitrary number of fields in the record? (define triad (make-record-layout (quote (pid env num)))) (define t (record triad pid "LOL" 5)) thanks, Max.
