1	# src/effect: the three foreign effects snap runs programs through. Each is
2	# written twice, in C for the native lane and in JS for the interpreter, and
3	# each reads a wire the planners in src/argv.bend and src/par.bend make.
4	import Base
5	
6	# the program and its arguments, NUL separated (`wire`), run with no shell
7	# between. The answer is the exit status on its own first line, then stdout
8	# and stderr.
9	def snaprun.exec(cmd: String) -> IO(String):
10	  import "./exec.c"
11	  import "./exec.js"
12	
13	# a program started and left running, answering with its pid, or 0 when it
14	# could not be started. The arguments arrive as `wire` makes them. The effect above
15	# waits for what it runs and reads it to the end; this one waits for nothing,
16	# and gives the child a session and a /dev/null of its own so it holds no pipe
17	# open behind it.
18	def snaprun.start(cmd: String) -> IO(String):
19	  import "./start.c"
20	  import "./start.js"
21	
22	# several programs run at once, answering with every exit status in the order
23	# the jobs were given. The fields arrive as `par.plan` joins them. The children
24	# write into a directory rather than down a pipe, and `par` below reads those
25	# files back, so this answers statuses alone.
26	def snaprun.par(cmd: String) -> IO(String):
27	  import "./par.c"
28	  import "./par.js"