Re^4: Multiple asynchronous execution of commands

That worked nicely. Code snippet:

my $mysql = q{/usr/local/mysql/bin/mysql --host= [...]};
my @fh;
my $i = 0;
for my $sql (
             q{SELECT id INTO OUTFILE \'/sort/clh/na\' FROM addr},
             q{SELECT id INTO OUTFILE \'/sort/clh/ne\' FROM email},
             q{SELECT id INTO OUTFILE \'/sort/clh/np\' FROM phone}
            ) {
    my $cmd = "echo $sql | $mysql";
    open( $fh[$i++], '-|', $cmd )
      or die "Failed opening $sql: $!\n";
}
say "All spawned - waiting";
for my $i (0..$#fh) {
    while (defined (my $line = readline( $fh[ $i ] ))) {
        print "FH$i: $line";
    }
}
[download]

And as you pointed out, I could use IO::Select if I cared about knowing when each command finished.

Comment on Re^4: Multiple asynchronous execution of commands Download Code

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Re^5: Multiple asynchronous execution of commands by BrowserUk (Patriarch) on Jan 23, 2016 at 01:35 UTC
# work around parsing problem with <$fh$i> below You can avoid the unnecessary assignment by using readline, the function that underlies that version of the diamond operator, like so: `while (defined (my $line = readline( $fh[ $i ] ) ) ) {` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". I knew I was on the right track :) In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re^6: Multiple asynchronous execution of commands by ibm1620 (Hermit) on Jan 23, 2016 at 23:03 UTC
Modified code snippet above.	[reply]