ralph@himmel:~$ while true; do echo "inputstream"; sleep 1; done | sed -e "s/^/`date` /"
Di 15. Jul 21:44:40 CEST 2008 inputstream
Di 15. Jul 21:44:40 CEST 2008 inputstream
Di 15. Jul 21:44:40 CEST 2008 inputstream

#!/usr/bin/perl -w

pipe(LESE_HANDLE, SCHREIB_HANDLE);
my $Kind_pid = fork();

if ($Kind_pid) {
 close(LESE_HANDLE);
 my $old_handle = select(SCHREIB_HANDLE);
 $| = 1;
 print SCHREIB_HANDLE qx(mpstat 1 10);
 close(SCHREIB_HANDLE);
 wait;
 select($old_handle);
} else {
 close(SCHREIB_HANDLE);
 my $Speicher;
 while(defined($Speicher = <LESE_HANDLE>)) {
   print "Empfangen: $Speicher \n";
 }
 exit(0);
}

open(my $mpstat, "mpstat 1 10|") or ...

#!/usr/bin/perl

use strict;
use warnings;

my $cmd = '/usr/bin/vmstat 1 10|';

open(my $fh, $cmd)
        or die "Error executing vmstat: $!";

while ( my $line = <$fh> ) {
        print $line;
        print '-' x 70, "\n";
}
close($fh);

procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
----------------------------------------------------------------------
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
----------------------------------------------------------------------
 1  0     64 954680  35300 272440    0    0    11    18   43   21  3  0 97  0
----------------------------------------------------------------------
 0  0     64 954176  35300 272440    0    0     0     0 1082  397  3  0 97  0
----------------------------------------------------------------------
 0  0     64 954176  35300 272440    0    0     0     0 1084  397  1  0 99  0
----------------------------------------------------------------------
 1  0     64 954176  35308 272440    0    0     0    48 1084  388  1  1 97  1
----------------------------------------------------------------------
 0  0     64 954208  35308 272440    0    0     0     0 1084  398  2  0 98  0
----------------------------------------------------------------------
 0  0     64 954208  35308 272440    0    0     0     0 1081  378  1  0 99  0
----------------------------------------------------------------------
 1  0     64 954208  35308 272440    0    0     0     0 1084  395  1  1 98  0
----------------------------------------------------------------------
 0  0     64 954208  35308 272440    0    0     0     0 1081  375  2  0 98  0
----------------------------------------------------------------------
 0  0     64 954224  35308 272440    0    0     0     0 1084  400  1  0 99  0
----------------------------------------------------------------------
 0  0     64 954224  35308 272440    0    0     0     0 1081  362  2  0 98  0
----------------------------------------------------------------------

mpstat.pl
--8<--

#!/usr/bin/perl
# vim: set ts=4 sw=4 et sta:
use strict;
use warnings;


open my $pipe, './mpstat.sh |' or die "Pipe failed: $!\n";

while ( my $line = <$pipe> ) {

    my $time = localtime;

    local $, = ' ';
    print $time, $line;
}

close $pipe or die "Pipe failed: $!\n";

mpstat.sh
--8<--
#!/bin/bash

for x in 1 2 3; do
    echo "Wert $x"
    sleep 1
done

Wed Jul 16 17:29:06 2008 Wert 1
Wed Jul 16 17:29:07 2008 Wert 2
Wed Jul 16 17:29:08 2008 Wert 3

#!/usr/bin/perl
# vi:ts=4 sw=4 et:
use strict;
use warnings;

my $cmd = '/usr/bin/vmstat 1 3';

$| = 1;

open my $pipe, '-|', $cmd or die "$cmd: can't read from pipe: $!\n";

while ( my $line = <$pipe> ) {
    my $time = localtime;

    local $, = ' '; # Leerzeichen explizit angegeben (wg. Highlighting); war $"
    print $time, $line;
}

close $pipe;