Array output

muizelaar has asked for the wisdom of the Perl Monks concerning the following question:

I have written this small script to list all our Solaris packages on our servers. I require that it only lists our own application software listed in the Array. However if there are no packages listed I would like the script to be able to tell me there are no packages installed rather than show a blank screen. I have played around with various methods but cant seem to get anything to work, Any help would be appreciated.

#!/usr/bin/perl -w
use Cwd;
my $dir = getcwd;
my $newdir = "/opt/DSPKG";
my $pkg = "DSDSLVP*";
my $PKG = "DSAPEVP*";

#Changes directory
chdir($newdir) || die "Can't Chdir to $newdir: $!";

        system("pkginfo $pkg $PKG > /tmp/pkglist 2> /tmp/vperror");
        open(MYFILE, "/tmp/pkglist") || die "can't open file: $!";
        @stuff=<MYFILE>;
print "\n";
foreach my $file (@stuff) {eval {
print "$file";
}}


print "\n\n";
print "Press ENTER to Continue?";
      my $answer = <STDIN>;
      chomp $answer;
[download]

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Replies are listed 'Best First'.
Re: Array output by moritz (Cardinal) on Sep 17, 2007 at 11:10 UTC
`if (@stuff){ print join("\n", @stuff, ''); } else { print "No custom packages installed"; }` [download] Perl 6 in German	[reply] [d/l]
Re^2: Array output by muizelaar (Sexton) on Sep 17, 2007 at 11:31 UTC
Hi Thanks for that its working now. I tried a simmillar approch but I think I didnt use the Join function as part of my script. Still learning :)	[reply]
Re: Array output by cdarke (Prior) on Sep 17, 2007 at 11:50 UTC
I notice that you do not delete the temporary file at end, but do you need it? You can read the output from a program direct into an array (or scalar) with qx (or `back-ticks`): `@stuff = qx(pkginfo $pkg $PKG 2> /tmp/vperror);` [download] This replaces the system and open commands, and the read. stderr is not affected, so you might want to unlink the file.	[reply] [d/l]
Re: Array output by shmem (Chancellor) on Sep 17, 2007 at 14:08 UTC
Something that immediately caught my eye: `foreach my $file (@stuff) {eval { print "$file"; }}` [download] Why the eval ? Don't double-quote single variables, it's a bad habit unless needed. --shmem _($_=" "x(1<<5)."?\n".q·/)Oo. G°\ / /\_¯/(q / ---------------------------- \__(m.====·.(_("always off the crowd"))."· ");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}	[reply] [d/l]