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|
use "die"
use "errno"
use "execvp"
use "fmt"
use "result"
use "syswrap"
use "wait"
pkg std =
const run : (cmd : byte[:][:] -> waitstatus)
const spork : (cmd : byte[:][:] -> result((pid, fd, fd), errno))
const espork : (cmd : byte[:][:] -> result((pid, fd, fd, fd), errno))
const filterfd : (fd : fd, cmd : byte[:][:] -> result(pid, errno))
;;
const run = {cmd
var pid
pid = fork()
/* error */
if pid < 0
-> `Waiterror
elif pid == 0
execvp(cmd[0], cmd)
die("failed exec\n")
else
-> wait(pid)
;;
}
const spork = {cmd
var infds : fd[2], outfds : fd[2]
var err
/* open up pipes */
err = pipe(&infds)
if err != Enone
-> `Err err
;;
err = pipe(&outfds)
if err != Enone
-> `Err err
;;
match sporkfd(cmd, infds, outfds, [-1, 2])
| `Ok pid:
/* close unused fd ends */
close(infds[0]);
close(outfds[1]);
-> `Ok (pid, infds[1], outfds[0])
| `Err m:
-> `Err m
;;
}
const espork = {cmd
var infds : fd[2], outfds : fd[2], errfds : fd[2]
var err
/* open up pipes */
err = pipe(&infds)
if err != Enone
-> `Err err
;;
err = pipe(&outfds)
if err != Enone
-> `Err err
;;
err = pipe(&errfds)
if err != Enone
-> `Err err
;;
match sporkfd(cmd, infds, outfds, errfds)
| `Ok pid:
/* close unused fd ends */
close(infds[0]);
close(outfds[1]);
close(errfds[1]);
-> `Ok (pid, infds[1], outfds[0], errfds[0])
| `Err m:
-> `Err m
;;
}
const filterfd = {fd, cmd
var outfds : fd[2]
var err
err = pipe(&outfds)
if err != Enone
-> `Err err
;;
match sporkfd(cmd, [fd, -1], outfds, [-1, 2])
| `Ok pid:
dup2(outfds[0], fd)
close(outfds[0]);
close(outfds[1]);
-> `Ok pid
| `Err e:
-> `Err e
;;
}
const sporkfd = {cmd, infds, outfds, errfds
var pid
pid = fork()
/* error */
if pid < 0
/* we don't want to leak the pipe fds on error */
close(infds[0]);
close(infds[1]);
close(outfds[0]);
close(outfds[1]);
close(errfds[0]);
close(errfds[1]);
-> `Err (pid : errno)
/* child */
elif pid == 0
/* stdin/stdout for our communication. */
match dup2(infds[0], 0)
| `Ok _: /* nothing */
| `Err e: -> `Err e
;;
match dup2(outfds[1], 1)
| `Ok _: /* nothing */
| `Err e: -> `Err e
;;
match dup2(errfds[1], 2)
| `Ok _: /* nothing */
| `Err e: -> `Err e
;;
/* close the fds we duped */
if infds[0] != 0
close(infds[0])
;;
if outfds[1] != 1
close(outfds[1])
;;
if errfds[1] != 2
close(errfds[1])
;;
/* close the unused ends */
close(infds[1])
close(outfds[0])
close(errfds[0])
execvp(cmd[0], cmd)
/* if fork succeeds, we never return */
die("exec failed")
/* parent */
else
-> `Ok pid
;;
}
|
