The Process module is a collection of methods used to manipulate
processes.
|
class methods
|
|
egid
|
Process.egid
-> aFixnum
|
|
Returns the effective group id for this process.
|
|
egid=
|
Process.egid= aFixnum
-> aFixnum
|
|
Sets the effective group id for this process.
|
|
euid
|
Process.euid
-> aFixnum
|
|
Returns the effective user id for this process.
|
|
euid=
|
Process.euid= aFixnum
|
|
Sets the effective user id for this process.
Not available on all platforms.
|
|
exit!
|
Process.exit!( aFixnum=-1 )
|
|
Exits the process immediately.
No exit handlers are run. aFixnum is returned to the underlying system as the exit
status.
|
|
fork
|
Process.fork [{ block } ]
-> aFixnum or nil
|
|
See
Kernel::fork
on page 416.
|
|
getpgid
|
Process.getpgid( anInteger )
-> anInteger
|
|
Returns the process group id for the given process id.
Not available on all platforms.
|
Process.getpgid(Process.ppid())
|
» |
32438
|
|
|
getpgrp
|
Process.getpgrp
-> anInteger
|
|
Returns the process group id for this process.
Not available on all platforms.
|
Process.getpgid(0)
|
» |
32438
|
|
Process.getpgrp
|
» |
32438
|
|
|
getpriority
|
Process.getpriority( aKind, anInteger ) -> aFixnum
|
|
Gets the
scheduling priority for specified process, process group, or
user. aKind indicates the kind of entity to find:
one of
Process::PRIO_PGRP
,
Process::PRIO_USER
, or
Process::PRIO_PROCESS
. anInteger is an id indicating the particular process,
process group, or user (an id of 0 means current).
Lower priorities are more favorable for
scheduling. Not available on all platforms.
|
Process.getpriority(Process::PRIO_USER, 0)
|
» |
0
|
|
Process.getpriority(Process::PRIO_PROCESS, 0)
|
» |
0
|
|
|
gid
|
Process.gid
-> aFixnum
|
|
Returns the group id for this process.
|
|
gid=
|
Process.gid= aFixnum
-> aFixnum
|
|
Sets the group id for this process.
|
|
kill
|
Process.kill( aSignal, [ aPid ]+ ) -> aFixnum
|
|
Sends the given signal to the specified process id(s),
or to the
current process if aPid is zero. aSignal may be an
integer signal number or a POSIX signal name (either with or
without a SIG prefix). If aSignal is negative (or
starts with a ``-'' sign), kills process groups instead
of processes. Not all signals are available on all platforms.
trap("SIGHUP") { close_then_exit }
Process.kill("SIGHUP", 0)
|
|
|
pid
|
Process.pid -> aFixnum
|
|
Returns the process id of this process.
Not available on all platforms.
|
|
ppid
|
Process.ppid -> aFixnum
|
|
Returns the process id of the parent of this process.
Always returns 0 on NT.
Not available on all platforms.
print "I am ", Process.pid, "\n"
Process.fork { print "Dad is ", Process.ppid, "\n" }
|
produces:
|
|
setpgid
|
Process.setpgid( aPid, anInteger )
-> 0
|
|
Sets the process group id of aPid (0 indicates this
process) to anInteger.
Not available on all platforms.
|
|
setpgrp
|
Process.setpgrp
-> 0
|
|
Equivalent to setpgid(0,0).
Not available on all platforms.
|
|
setpriority
|
Process.setpriority( kind, anInteger, anIntPriority )
-> 0
|
|
See
Process#getpriority
.
|
Process.setpriority(Process::PRIO_USER, 0, 19)
|
» |
0
|
|
Process.setpriority(Process::PRIO_PROCESS, 0, 19)
|
» |
0
|
|
Process.getpriority(Process::PRIO_USER, 0)
|
» |
19
|
|
Process.getpriority(Process::PRIO_PROCESS, 0)
|
» |
19
|
|
|
setsid
|
Process.setsid
-> aFixnum
|
|
Establishes this process as a new session and process group
leader, with no controlling tty.
Returns the session id.
Not available on all platforms.
|
|
uid
|
Process.uid
-> aFixnum
|
|
Returns the user id of this process.
|
|
uid=
|
Process.uid= anInteger
-> aNumeric
|
|
Sets the (integer) user id for this process.
Not available on all platforms.
|
|
wait
|
Process.wait
-> aFixnum
|
|
Waits for any child process to exit and returns the process id
of that child.
Raises a SystemError if there are no child processes.
Not available on all platforms.
|
Process.fork { exit 1; }
|
» |
1500
|
|
Process.wait
|
» |
1500
|
|
|
wait2
|
Process.wait2
-> anArray
|
|
Waits for any child process to exit and returns an array
containing the process id and the exit status
of that child.
Raises a SystemError if there are no child processes.
|
Process.fork { exit 1 }
|
» |
1503
|
|
Process.wait2
|
» |
[1503, 256]
|
|
|
waitpid
|
Process.waitpid( aPid, anInteger=0 )
-> aPid
|
|
Waits for the given child process to exit. anInteger may be
a logical or of the flag value
Process::WNOHANG
(do not block if no child available)
or
Process::WUNTRACED
(return stopped children that haven't
been reported).
Not all flags are available on all platforms, but a flag value
of zero will work on all platforms.
|
include Process
|
|
pid = fork { sleep 3 }
|
» |
1506
|
|
Time.now
|
» |
Sun Jun 09 00:20:09 CDT 2002
|
|
waitpid(pid, Process::WNOHANG)
|
» |
nil
|
|
Time.now
|
» |
Sun Jun 09 00:20:09 CDT 2002
|
|
waitpid(pid, 0)
|
» |
1506
|
|
Time.now
|
» |
Sun Jun 09 00:20:12 CDT 2002
|
|
|
waitpid2
|
Process.waitpid2( aPid, anInteger=0 )
-> anArray
|
|
Waits for the given child process to exit, returning that
child's process id and exit status. anInteger may be
a logical or of the flag value
Process::WNOHANG
(do not block if no child available)
or
Process::WUNTRACED
(return stopped children that haven't
been reported).
Not all flags are available on all platforms, but a flag value
of zero will work on all platforms.
|
Extracted from the book "Programming Ruby -
The Pragmatic Programmer's Guide"
Copyright
©
2001 by Addison Wesley Longman, Inc. This material may
be distributed only subject to the terms and conditions set forth in
the Open Publication License, v1.0 or later (the latest version is
presently available at http://www.opencontent.org/openpub/)).
Distribution of substantively modified versions of this document is
prohibited without the explicit permission of the copyright holder.
Distribution of the work or derivative of the work in any standard
(paper) book form is prohibited unless prior permission is obtained
from the copyright holder.
