Re^2: open (to read) and kill a pipe to a pipe

Thanks! This looks promesing... but I can't figure it out.

I tried open2 (since I don't need the stderr from open3), but I don't even get the output of mycommand to show up...
what should I put in the while(< ??? >)... or did I even use the open2 command properly?

use IPC::Open2;

$file = $ARGV[0];

local *FRGZ;
local *TOGZ;
local *FRCMD;

$pid1 = open2(*FRGZ, *TOGZ, "gzip -dc $file");
$pid2 = open2(*FRCMD, '<FRGZ', 'mycommand');

while (<*FRCMD>)
{

    print;
}
[download]

maybe someone can provide an example of how to make this work...
My idea here is for the command "gzip -dc $file" to pipe its output to *FRGZ. Then I would pipe *FRGZ into "mycommand" and the output would be on *FRCMD .... ???

Comment on Re^2: open (to read) and kill a pipe to a pipe Download Code

Replies are listed 'Best First'.
Re^3: open (to read) and kill a pipe to a pipe by ikegami (Patriarch) on Aug 26, 2010 at 22:22 UTC
open2 mixes STDERR into STDOUT, its arguments are "backwards", and it just ends up calling open3 anyway. I avoid it. `use strict; use warnings; use IPC::Open3 qw( open3 ); my $file = $ARGV[0]; open(local TO_CHAIN, '<', $file) or die("Can't open \"$file\": $!\n"); my $gz_pid = open3('<TO_CHAIN, local PIPE, '>STDERR', 'gzip -dc'); my $mc_pid = open3('<PIPE', local *FR_CHAIN, '>STDERR', 'mycommand'); while (<FR_CHAIN>) { print; }` [download]	[reply] [d/l]

Replies are listed 'Best First'.

Re^3: open (to read) and kill a pipe to a pipe
by ikegami (Patriarch) on Aug 26, 2010 at 22:22 UTC

open2 mixes STDERR into STDOUT, its arguments are "backwards", and it just ends up calling open3 anyway. I avoid it.

use strict;
use warnings;

use IPC::Open3 qw( open3 );

my $file = $ARGV[0];
open(local *TO_CHAIN, '<', $file)
   or die("Can't open \"$file\": $!\n");

my $gz_pid = open3('<TO_CHAIN, local *PIPE, '>STDERR', 'gzip -dc');
my $mc_pid = open3('<PIPE', local *FR_CHAIN, '>STDERR', 'mycommand');

while (<FR_CHAIN>) {
   print;
}
[download]

[reply]
[d/l]