@cmd = ( q{/bin/tcsh}, "-c", ...);
system(@cmd) == 0 or warn;
[download]

Also the construct 'echo-like "..." | sh' to send commands to the shell seems ugly, just use perl to generate the necessary shell script, and execute it

A small example to make things clearer, I hope.

% steph@ape (/home/stephan/t2) %
% ls -1                  
bag'cmds
driver.pl
more cmds

% steph@ape (/home/stephan/t2) %
% cat $'bag\'cmds' 
echo just another shell hacker
echo just another perl hacker

% steph@ape (/home/stephan/t2) %
% cat 'more cmds' 
echo .done

% steph@ape (/home/stephan/t2) %
% cat driver.pl
#!/bin/perl

use strict;
use warnings;
$|++;
use Data::Dumper;

# make this line after the q op. valid shell
my $main_cmd = q{
   cat bag\'cmds "more cmds" | sh
   };


my @cmd = ( '/bin/ksh', '-c', $main_cmd );
print Dumper(\@cmd);

print "\n./bin/sh -c '/bin/ksh -c ...'\n";
system(@cmd) == 0 or warn;

print "\n.directly: at the mercy of your system shell\n ->";
system('echo $0') == 0 or warn;
print "\n";
system($main_cmd) == 0 or warn;

print "\n.generating script\n";

my $cmd_file = qq{temp$$.sh};
open my $outh, '>', $cmd_file or die;

print $outh <<"EOSHELL";
$main_cmd
EOSHELL

system('cat', '-evnt', $cmd_file) == 0 or warn;
system('/bin/ksh', $cmd_file) == 0 or warn;
unlink $cmd_file;
__END__

% steph@ape (/home/stephan/t2) %
% perl driver.pl
$VAR1 = [
          '/bin/ksh',
          '-c',
          '
   cat bag\\\'cmds "more cmds" | sh
   '
        ];

./bin/sh -c '/bin/ksh -c ...'
just another shell hacker
just another perl hacker
.done

.directly: at the mercy of your system shell
 ->sh

just another shell hacker
just another perl hacker
.done

.generating script
     1  $
     2     cat bag\'cmds "more cmds" | sh$
     3     $
just another shell hacker
just another perl hacker
.done
[download]