[Chicago-talk] trouble caputuring return value

Ted Zlatanov tzz at lifelogs.com
Wed Mar 31 10:03:17 PDT 2010

On Wed, 31 Mar 2010 16:13:27 +0300 Shlomi Fish <shlomif at iglu.org.il> wrote: 

SF> You should not expect Perl to assign to a variable in the main program by 
SF> evaluating an assignment to its name in a different process. To communicate 
SF> with a child process you need inter-process communications, such as anonymous 
SF> pipes, sockets, named pipes, System V IPC, mmap, using the file-system for 
SF> that, etc. Please read a little about UNIX multi-processing basics (a lot of 
SF> which is also relevant to Windows and other operating systems). 
SF> You cannot use return to return an arbitrary Perl value from a program. It 
SF> only works for functions. As far as C and UNIX are concerned, everything that 
SF> comes out of a process must be in sequences of octets. You need to use 
SF> "print()" on something to emit it to the outside somehow.

If shared memory is a possibility, Tie::ShareLite makes it *really* easy
to share information persistently between programs.

Richard could also look into wxWidgets, which would make the input
reader better and wouldn't depend on gnome-terminal.  If he explains
more about why he's splitting the task into a reader and a processor,
I'm sure he'd get more specific suggestions.


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