Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??

While I'm not completely sure of what you want, it appears to me you are looking for something like a "datawaiting()" call instead of an end-of-file.
Here's a (somewhat) minimal change to your program with the end-of-file replaced :)

#!/usr/bin/perl use diagnostics; use strict 'subs'; use strict 'refs'; use Socket; use IO::Handle; my $child; #filehandle to child process my $parent; #filehandle to parent process my $pid; #Process ID of child process socketpair($child, $parent, AF_UNIX, SOCK_STREAM, PF_UNSPEC) or die "socketpair: $! +"; $child->autoflush(1); $parent->autoflush(1); if ($pid = fork()) { #parent close $parent or die "close: $!\n"; sleep 1; print STDOUT time%1000, ": polling child\n"; if (not datawaiting($child)) { ##### CHANGE +D print STDOUT time%1000, ": no input from child yet\n"; } else { my $line = <$child>; chomp $line; print STDOUT time%1000, ": received <$line>\n"; } } else { #child die "cannot fork: $!" unless defined $pid; close $child or die "close: $!\n"; print STDOUT time%1000, ": child started\n"; sleep 5; print {$parent} time%1000, ": child printed\n"; close $parent or die "close: $!\n"; exit; } sub datawaiting ####### CHANGED see perldoc -f select { my $rin = my $win = my $ein = ''; vec($rin, fileno(shift), 1) = 1; return scalar select my $rout = $rin, my $wout = $win, my $eout = $e +in, 0; }

Outputs:

277: child started 278: polling child 278: no input from child yet

Is that what you were looking for ?


In reply to Re^3: eof() blocking by tybalt89
in thread eof() blocking by azadian

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others avoiding work at the Monastery: (4)
As of 2024-03-29 05:02 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found