using perl script to invoke cleartool commands using fmt - perl

Question

I use Perl scripts to run commands for several users in several VOBs on ClearCase. I have a list of the VOBs which I read in from a text file. I then loop on that list and do whatever ClearCase command I am trying to do. However, this time the script does not seem to work. If I print out the command to the screen then go and copy and paste it at the prompt it works fine. It just will not executed from the Perl script. The only difference I saw was the fmt characters but even when I remove that it does not execute. I tried first putting the fmt on the line directly then tried setting them to variables. You will see the first comment line is the one that failed but I left it there as an example of what I tried. The last two comments are from another script that I run like this that does work.
Code:
#! /usr/local/bin/perl -w
use strict;
open(VOBS,"vobs.txt") || die "Can't open: !$\n";
my $u = '%u';
my $a ='%Ad';
my $n ='%N/n';
my $user='john';
my $ct = '/usr/atria/bin/cleartool';
while(my $newvobs=<VOBS>){
chomp($newvobs);
my $tag = $newvobs;
print "\n $tag \n";
print " $ct lstype -kind brtype -invob $tag | grep $user ";
`$ct lstype -kind brtype -invob $tag | grep $user`;
# `/usr/atria/bin/cleartool lstype -kind brtype -invob $tag -fmt '%u %Ad %N/\n' `;
# print "\n cleartool rmtag -view $tag \n";
#`/usr/atria/bin/cleartool rmtag -view $tag `;
}
close(VOBS);

Answer 1

Actually Your program runs, but is does not print anything.
Example:
#!/usr/bin/perl
use strict;
use warnings;
my $cmd = "cat";
`$cmd $0 | grep warning`;
Output: (nothing)
Easiest to fix. Last line
print `$cmd $0 | grep warning`
Output:
use warnings;
print `$cmd $0 | grep warning`;
If You need the exit code, replace last line with
my $exit = system("$cmd $0 | grep warning");
print $exit;
Output:
use warnings;
my $exit = system("$cmd $0 | grep warning");
0
Or use open to process output:
open my $fh, "$cmd $0 | grep warning|" or die;
while (<$fh>) { print $_; }
close $fh;
Output:
use warnings;
open my $fh, "$cmd $0 | grep warning|" or die;
But I could suggest something like bellow. Using AUTOLOAD the clearcase commands can be used as internal perl commands.
#!/usr/bin/perl
use strict;
use warnings;
sub AUTOLOAD {
(my $sub = $::AUTOLOAD) =~ s/.*:://;
print "---\n";
system("time $sub #_");
print "---\n";
}
my $cmd = "cat";
eval "$cmd($0)";
Output:
---
#!/usr/bin/perl
use strict;
use warnings;
sub AUTOLOAD {
(my $sub = $::AUTOLOAD) =~ s/.*:://;
print "---\n";
system("time $sub #_");
print "---\n";
}
cat($0);
0.00user 0.00system 0:00.00elapsed 400%CPU (0avgtext+0avgdata 2112maxresident)k
0inputs+0outputs (0major+174minor)pagefaults 0swaps
---

Answer 2

For reference, here is a perl script which uses -fmt, "Finding the latest baseline for a component":
Example:
ccperl StreamComp.pl mystream#\pvobtag | findstr {component}
Script "streamcomp.pl":
#!/usr/bin/perl -w
my $cmdout = `cleartool desc -fmt '%[latest_bls]CXp' stream:$ARGV[0]`;
my #baselines = split(/,/,$cmdout);
foreach $baseline (#baselines)
{
$compname=`cleartool desc -fmt '%[component]p' $baseline`;
printf("%-30s \t %s\n", $compname, $baseline);
}
It is a program working for a ClearCase UCM environment, but it could give you an idea of the kind of working statements (try without grep first) you could try to reproduce in your own base ClearCase program.