Re: exec function does not return command prompt

in reply to exec function does not return command prompt

When I execute the parent script I receive the following output:
/liwidata/dev/tmp/jmg/dev/library> ./test1.pl
In test1 the parent pid is 21348; the child pid is 21349
All done!
/liwidata/dev/tmp/jmg/dev/library> In test2.pl the pid is 21349
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As you can see the command prompt does not appear at the conclusion of the child script.

Are you sure? To me it looks like the prompt is right there, _before_ the "In test2.pl" output.

Instead of Ctrl-C, have you tried just entering a command? (or pressing enter to simply go to the next line)

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Re^2: exec function does not return command prompt by casman46 (Initiate) on Aug 18, 2014 at 12:42 UTC
Crackers2: Thank you for your reply to my question. It appears that I do not understand how the fork function works. Nevertheless, since both test1.pl and test2.pl do exit, shouldn't I see a command prompt at the conclusion of each one?	[reply]
Re^3: exec function does not return command prompt by Crackers2 (Parson) on Aug 19, 2014 at 15:03 UTC
No. That's not how the shell works. Either it will wait for both to exit before showing the (one) prompt, or it will show the prompt after a certain proces exits and finish the other one in the background; in that case you won't get a new prompt after the background one exits. I'm not exactly sure when it decides to keep stuff in the foreground or run them in the background. In your case I think it's running both in the foreground, but due to buffering the output from test2 just happens to show up after the prompt	[reply]

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