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|
use "die.use"
use "execvp.use"
use "fmt.use"
use "result.use"
use "syswrap.use"
pkg std =
const spork : (cmd : byte[:][:] -> result((pid, fd, fd), int))
const sporkfd : (cmd : byte[:][:], infd : fd, outfd : fd -> result(pid, int))
;;
const spork = {cmd
var infds :fd[2], outfds : fd[2]
var err
/* open up pipes */
err = pipe(&infds)
if err != 0
-> `Fail (-err castto(int))
;;
err = pipe(&outfds)
if err != 0
-> `Fail (-err castto(int))
;;
match sporkfd(cmd, infds[0] castto(fd), outfds[1] castto(fd))
| `Ok pid:
/* close unused fd ends */
close(infds[0]);
close(outfds[1]);
-> `Ok (pid, infds[1], outfds[0])
| `Fail m:
-> `Fail m
;;
}
const sporkfd = {cmd, infd, outfd
var pid
pid = fork()
/* error */
if pid == -1
-> `Fail -1
/* child */
elif pid == 0
/* stdin/stdout for our communication. */
if dup2(infd castto(fd), 0) != 0
fatal("unable to set stdin\n")
;;
if dup2(outfd castto(fd), 1) != 1
fatal("unable to set stdout\n")
;;
close(infd)
close(outfd)
execvp(cmd[0], cmd) < 0
fatal("failed to exec {}\n", cmd[0])
/* parent */
else
-> `Ok pid
;;
}
|
