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From: Stephane Chazelas <stephane.chazelas@gmail.com>
To: Joey Pabalinas <joeypabalinas@gmail.com>,
	Bart Schaefer <schaefer@brasslantern.com>,
	Zsh hackers list <zsh-workers@zsh.org>
Subject: Re: "echo | ps -j $(:) | cat | cat | cat" runs components in different process groups
Date: Tue, 27 Mar 2018 11:17:12 +0100	[thread overview]
Message-ID: <20180327101712.GA5473@chaz.gmail.com> (raw)
In-Reply-To: <20180324173406.GA18604@chaz.gmail.com>

2018-03-24 17:34:06 +0000, Stephane Chazelas:
[...]
> That means, that one can't ^C
> 
> sleep 1 | cat $(sleep 10)
> 
> for instance.
[...]

For the record, while

/bin/sleep 1 | cat $(/bin/sleep 10) | cat

can be interrupted in ksh93,

ksh93$ /bin/sleep 1 | cat $(ps -jf>&2) $(/bin/sleep 20)
UID        PID  PPID  PGID   SID  C STIME TTY          TIME CMD
chazelas 16259  5079 16259 16259  0 10:58 pts/7    00:00:00 /bin/zsh
chazelas 16281 16259 16281 16259  0 10:59 pts/7    00:00:00 ksh93 -o emacs
chazelas 16355 16281 16355 16259  0 11:02 pts/7    00:00:00 /bin/sleep 1
chazelas 16356 16281 16281 16259  0 11:02 pts/7    00:00:00 ps -jf
chazelas 16357 16281 16281 16259  0 11:02 pts/7    00:00:00 /bin/sleep 20

Cannot (see how ps -j and sleep 20 run (concurrently!) in a
different process group from sleep 1) like in zsh (and a ^Z
while sleep 1 is running causes a deadlock).

One difference with zsh is that it can't be worked around by
running that last pipe component in a subshell (as ksh93 fakes
subshells instead of forking).

-- 
Stephane


  parent reply	other threads:[~2018-03-27 10:17 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-23 16:16 Stephane Chazelas
2018-03-23 23:36 ` Bart Schaefer
2018-03-24  5:19   ` Bart Schaefer
2018-03-24  8:05     ` Joey Pabalinas
2018-03-24 17:34       ` Stephane Chazelas
2018-03-24 22:23         ` Bart Schaefer
2018-03-25  7:00           ` Stephane Chazelas
2018-03-25  8:26             ` Stephane Chazelas
2018-03-25  7:48           ` Stephane Chazelas
2018-03-25 18:09             ` Stephane Chazelas
2018-03-27 10:17         ` Stephane Chazelas [this message]
2018-03-24 22:09       ` Bart Schaefer
2018-04-10 11:45         ` Peter Stephenson
2018-04-10 13:59           ` Peter Stephenson
2018-04-11 22:10             ` Bart Schaefer
2018-04-12 16:23               ` Peter Stephenson
2018-04-15 16:23                 ` Stephane Chazelas
2018-04-15 17:38                   ` Bart Schaefer
2018-04-15 18:58                     ` Stephane Chazelas
2018-04-17  5:39                       ` Bart Schaefer
2018-04-17  9:19                         ` Peter Stephenson
2018-04-17 16:09                           ` Bart Schaefer
2018-04-17 16:27                             ` Bart Schaefer
2018-04-17 16:35                             ` Peter Stephenson
2018-04-17 17:52                               ` Bart Schaefer
2018-04-19  9:40                                 ` Peter Stephenson
2018-04-20  9:28                                   ` Forking earlier for background code Peter Stephenson
2018-04-20 10:01                                     ` Peter Stephenson
2018-04-20 12:54                                       ` Vin Shelton
     [not found]                                         ` <CGME20180420132008eucas1p1c297624e870975cd892c74254970faab@eucas1p1.samsung.com>
2018-04-20 13:20                                           ` Peter Stephenson
2018-04-20 16:01                                             ` Vin Shelton
2018-04-23  8:29                                     ` Peter Stephenson
2018-05-01  9:23                                       ` Peter Stephenson
     [not found]                                   ` <F3A62E38-24E2-4A62-8E19-F54C9B81E9E5@kba.biglobe.ne.jp>
2018-04-23 13:52                                     ` "echo | ps -j $(:) | cat | cat | cat" runs components in different process groups Peter Stephenson
2018-04-23 14:03                                       ` Peter Stephenson
     [not found]                                         ` <CGME20180423140859eucas1p2591bf1422614209979d4890383268c37@eucas1p2.samsung.com>
2018-04-23 14:08                                           ` Peter Stephenson
2018-04-23 15:29                                         ` Jun T.
2018-04-18  6:29                           ` Stephane Chazelas
2018-04-18 16:33                             ` Bart Schaefer
2018-04-10  9:53   ` Peter Stephenson
2018-03-25  7:38 ` Stephane Chazelas

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