loop inside system command

Hello , I am using the system command to excute a command inside my script , however I am trying to use an array inside that system command ,,, forexmaple , the command line is :

my $firstbuild = hi.bld
my @otherbuilds = q( low.bld hello.bld cow.bld ); 
system(qq(C:/execu $firstbuild @otherbuilds file.c));

knowing that the array @otherbuilds could have more or less builds than three. so I am trying to find a way to do somthing like this

system(qq(C:/execu $firstbuild low.bld hello.bld cow.bld file.c));

somehow read the array index and list them in an order .. I tried a loop within that command but system didn't like it . what do yall think .. thanks for hints

[stephen]

I'd recommend using the multi-argument variant of system().

system("C:\\execu", $firstbuild, @otherbuilds, 'file.c')
   and die "System command failed";

stephen

[abaxaba]

If I understand your question correctly, you'll need to execute system singularly, and build your loop around it, as opposed to in it

foreach ($firstbuild, @otherbuilds)
{
    system (qq(C:/execu $_ file.c));
}

One thing you may consider, esp. if @otherbuilds can grow to be sufficiently large: system is a double fork, in terms of processes spawned. One proc. for the system call, one for the actual command to run. If you're going to be calling system on more than a couple of items, you may consider doing something like so:

open (OUT, ">cmd.txt") || die "$!\n";
foreach ($firstbuild, @otherbuilds)
{
    print OUT "C:/execu $_ file.c\n";
}
close OUT;
system ("cmd.txt");

The reason? Instead of spawning 2N processes, you'll spawn only N+1. 3 or 4 system calls probably doesn't warrant the extra work. If you got 100 or so...well, you get the picture.



ÅßÅ×ÅßÅ "It is a very mixed blessing to be brought back from the dead." -- Kurt Vonnegut

[DS]

thanks to you all :)

[cidaris]

I got this to work:

my $command_line = "";
my $first_build = "hi.bld";
my @other_builds = qw( low.bld hello.bld cow.bld );
$command_line = "c:\\execu $first_build";
$command_line .= " " . shift @other_builds while (@other_builds);
$command_line .= " file.c";
print "$command_line\n";
system "$command_line\n";



Hope it helps.
cidaris

[RMGir]

Interesting, cidaris. But have you ever used the join command?

It would save you your loop on "while(@other_builds)".

$command_line = "c:\\execu $first_build "; # note trailing space
$command_line .= join " ", @other_builds;
$command_line .= " file.c";

The only downside here is that you wind up with 2 spaces between $first_build and file.c if there are no other_builds.

The problem goes away if you do everything in a join:

$command_line .= join " ", ("c:\\execu $first_build",@other_builds,"fi
+le.c");


--
Mike