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Re: Checking executability for asynchronous commands
From: |
Chet Ramey |
Subject: |
Re: Checking executability for asynchronous commands |
Date: |
Fri, 25 Dec 2020 16:51:56 -0500 |
User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 |
On 12/25/20 4:40 AM, Markus Elfring wrote:
Hello,
I am looking for another bit of clarification according to an implementation
detail.
The manual is providing the following information.
https://git.savannah.gnu.org/cgit/bash.git/tree/doc/bash.1?id=76404c85d492c001f59f2644074333ffb7608532#n627
“…
If a command is terminated by the control operator &, the shell
executes the command in the background in a subshell. The shell does not wait for
the command to finish, and the
return status is 0.
…”
Thus I observe a behaviour like the following for a simple test with the
software “bash 5.0.18-3.1” according to a “program” which does not exist here.
elfring@Sonne:~> xy &
[1] 4063
xy: Befehl nicht gefunden
[1]+ Exit 127 xy
Yes, the child process exits with status 127, but $? is set to 0, as POSIX
requires. If you want the exit status of the child process, add `wait $!'
when you are ready to use the status, which will set $? to 127.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU chet@case.edu http://tiswww.cwru.edu/~chet/
- Checking executability for asynchronous commands, Markus Elfring, 2020/12/25
- Re: Checking executability for asynchronous commands, Andreas Kusalananda Kähäri, 2020/12/25
- Re: Checking executability for asynchronous commands,
Chet Ramey <=
- Re: Checking executability for asynchronous commands, Markus Elfring, 2020/12/26
- Re: Checking executability for asynchronous commands, Chet Ramey, 2020/12/26
- Re: Checking executability for asynchronous commands, Markus Elfring, 2020/12/27
- Re: Checking executability for asynchronous commands, Eli Schwartz, 2020/12/27
- Re: Checking executability for asynchronous commands, Greg Wooledge, 2020/12/28
- Re: Checking executability for asynchronous commands, Ilkka Virta, 2020/12/28
- Re: Checking executability for asynchronous commands, Eli Schwartz, 2020/12/28
- Re: Checking executability for asynchronous commands, Léa Gris, 2020/12/28
- Re: Checking executability for asynchronous commands, Eli Schwartz, 2020/12/28
- Re: Checking executability for asynchronous commands, Chet Ramey, 2020/12/29