Spawning child processes with extra control.
This extends the Eio.Process API with more control over file-descriptors.
class virtual mgr : object ... endval spawn_unix :
sw:Eio.Std.Switch.t ->
mgr ->
?cwd:Eio.Fs.dir Eio.Path.t ->
fds:(int * Fd.t * Private.Fork_action.blocking) list ->
?env:string array ->
?executable:string ->
string list ->
Eio.Process.tspawn_unix ~sw mgr ~fds args spawns a child process running the command args.
The arguments are as for Eio.Process.spawn, except that it takes a list of FD mappings for Fork_action.inherit_fds directly, rather than just flows for the standard streams.