src/effect.bend source

src/effect.bend on the hub · documented module

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