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@load "fork"
BEGIN {
# avoid instantiating PROCINFO prior to the fork
switch (pid = fork()) {
case -1:
printf "Error: fork failed with ERRNO %s\n", ERRNO
exit 1
case 0:
# child
fn = ("fork.tmp." PROCINFO["pid"])
printf "pid %s ppid %s\n", PROCINFO["pid"], PROCINFO["ppid"] > fn
exit 0
default:
# parent
erc = 1
fn = ("fork.tmp." pid)
if ((rc = wait()) < 0)
printf "Error: wait failed with ERRNO %s\n", ERRNO
else if (rc != pid)
printf "Error: wait returned %s instead of child pid %s\n", rc, pid
else if ((getline x < fn) != 1)
printf "Error: getline failed on temp file %s\n", fn
else {
close(fn) # needed on non-POSIX systems
expected = ("pid " pid " ppid " PROCINFO["pid"])
if (x != expected)
printf "Error: child data (%s) != expected (%s)\n", x, expected
else if ((rc = system("rm " fn)) != 0)
printf "Error removing temp file %s with ERRNO %s\n", fn, ERRNO
else
erc = 0
}
exit erc
}
}
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