Perl script is not kill tcl process - perl

Question

I have a perl script. It's not killing my tcl process. Here is what my process looks like:
UID 14439 10897 0 13:55:44 pts/26 0:00 /prod/bin/wish /prod/bin/q
Here is my perl script:
#!/usr/bin/env perl
#
# Simple kill script that allows users to kill specific processes
# using sudo
use BPub::Platform qw(solaris);
# Assume a taint mode type environment
$ENV{PATH} = '/opt/csw/bin:/usr/bin:/bin';
use strict;
use Getopt::Long;
if (!#ARGV) {
print "Usage: bkill [-9] pid <pid...>\n";
exit 1;
}
my $dashnine;
GetOptions('9' => \$dashnine);
# If the process name isn't in this hash, then you don't get to kill
# it
my %allowed_process_names = (
'dtsession' => 1,
'wish' => 1,
'compose' => 1,
);
# True if the given process name is one that we can kill
sub allowed_to_kill {
return $allowed_process_names{$_[0]};
}
# Takes a pid and returns the process name
sub process_name {
my ($pid) = #_;
my $out = `/usr/ucb/ps -c $pid | /bin/grep $pid | /bin/cut -b 25-1000`;
if ($?) {
print "Error running ps command: $!\n";
exit 2;
}
chomp($out);
return $out;
}
foreach my $pid (#ARGV) {
# tainted, remember?
if ($pid =~ /^(\d+)$/) {
my $safe_pid = $1;
my $name = process_name($safe_pid);
if (allowed_to_kill($name)) {
my #cmd = "/usr/bin/kill";
push (#cmd, '-9') if $dashnine;
push #cmd, $pid;
print "#cmd\n";
print "Killing $name ($pid)\n";
system(#cmd);
} else {
print "Not allowed to kill $safe_pid: $name.\n";
}
} else {
print "Invalid pid: must be a number: $pid\n";
}
}
When I run the script using sudo bkill PID. I get an error message saying:
bpub-xserver7-prod^UID118-> sudo bkill 14439
Password:
Not allowed to kill 14439: wish8.0.
Is there somethings that i can better in this script? How can i fix this problem that i am having getting rid of tcl process.

Answer 1

The program name your error message is emitting is wish8.0. So the simplest fix (and most strict) is to add 'wish8.0' => 1 to %allowed_process_names.
Or you could make your search less strict by doing something like:
my #allowed_process_names = qw(dtsession wish compose)
sub allowed_to_kill {
return scalar grep { index($_[0], $_) == 0 } #allowed_process_names
}
Which will find any string that starts with any of the allowed process names. (change to >= 0 or != -1 to allow it to match anywhere)
You could also use a regular expression instead. The following ones will match any program that starts with the provided program names. If you remove the leading caret, it would instead match them anywhere in the string.
my $allowed_process_names = qr/^(?:dtsession|wish|compose)/;
sub allowed_to_kill {
return $_[0] =~ /$allowed_process_names/;
}
or if you want to build up the regular expression programmatically:
my #allowed_process_names = qw(dtsession wish compose)
my $allowed_process_names = join('|', map quotemeta, #allowed_process_names);
$allowed_process_names = qr/^(?:$allowed_process_names)/;

Answer 2

# If the process name isn't in this hash, then you don't get to kill
# it
my %allowed_process_names = (
'dtsession' => 1,
'wish' => 1,
'compose' => 1,
);
...
my $out = `/usr/ucb/ps -c $pid | /bin/grep $pid | /bin/cut -b 25-1000`;
...
Not allowed to kill 14439: wish8.0.
Your ps pipeline is identifying the process as wish8.0 instead of wish or /prod/bin/wish. You will need to add an entry for "wish8.0" to this %allowed_process_names hash in order to use this perl script to kill this process.
If you were to look at /prod/bin/wish, you might find that it's a symbolic link to a file named wish8.0.