From: Dave Yost <Dave@Yost.com>
To: zsh-workers@zsh.org
Subject: shell function in the background?
Date: Wed, 25 Jun 2014 07:34:01 -0700 [thread overview]
Message-ID: <2C39FCD4-02E6-4957-B292-486065C24639@yost.com> (raw)
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Can a shell function tell if it’s part of a pipeline running in the background?
I want to write a shell function that traps SIGCONT and does one thing or another thing depending on whether the function is CONTinuing in the background.
Can’t see how to do it.
Furthermore, it’s not clear to me why a backgrounded function thinks its pid is the pid of the shell that spawned it.
0 Wed 0:12:34 DaveBook yost /tmp
250 Z% function foo() {
print foo says pid is $$
sleep 2
}
0 Wed 0:12:56 DaveBook yost /tmp
251 Z% foo & ps xl -t ttys004 | sort -k 2
[1] 26183
foo says pid is 25935
UID PID PPID CPU PRI NI VSZ RSS WCHAN STAT TT TIME COMMAND
0 25934 226 0 143 0 2503604 2316 - Ss s004 0:00.01 login -pf yost /bin/zsh
502 25935 25934 0 31 0 2500064 2512 - S s004 0:00.14 -zsh
502 26183 25935 0 163 5 2500064 588 - SN s004 0:00.00 -zsh
0 26184 25935 0 45 0 2433268 644 - R+ s004 0:00.00 ps xl -t ttys004
502 26185 26183 0 1074014208 5 2432764 500 - SN s004 0:00.00 sleep 2
502 26186 25935 0 1074104586 0 2432800 500 - R+ s004 0:00.00 sort -k 2
0 Wed 0:13:00 DaveBook yost /tmp
252 Z%
[1] + 26183 done foo
0 Wed 0:13:02 DaveBook yost /tmp
252 Z% print pid is $$
pid is 25935
0 Wed 0:21:00 DaveBook yost /tmp
253 Z%
I get the same thing even if I do this
function foo() {(
print foo says pid is $$
sleep 2
)}
foo &
or this
function foo() {
(
print foo says pid is $$
sleep 2
) &
}
foo
next reply other threads:[~2014-06-25 14:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-25 14:34 Dave Yost [this message]
2014-06-25 15:55 ` Bart Schaefer
2014-06-25 17:56 ` Philippe Troin
2014-07-24 11:41 ` Peter Stephenson
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