Re^2: Running Perl scripts from ssh

Here is the whole sarexec.pl for you.. #sarexec.pl code.....

#!/usr/bin/perl -w
#exec /usr/bin/perl /research-sar/sarexec.pl
use strict;

#starting sar....
if($ARGV[0] eq 'start')
{
 # Checking for correct parameters.. 
 if (exists $ARGV[1] && exists $ARGV[2] && exists $ARGV[3])
 {
   #print "present all things\n";
 }
 else 
 {
  #print "Missing parameters..cant continue..\n";
  
  exit;
 }


my $file_param;
my $file_location;
my $interval;

 $file_param = $ARGV[1];
 $file_location = $ARGV[2];
  open(FH,"> fileloc") or die"cant open the file";
  print FH $file_location or die"cant print to file";
  close(FH) or die "cant close the file";
 $interval = $ARGV[3];
  
   
   
  
my $pid =  fork();
  if($pid==0)
  {
  #print "In child";
  #print "$file_param";

   my $param1;
   open FH,"< $file_param" or die"cant open the file";
   #print "$file_param";
   $param1 = <FH>;
   close FH or die "cant close the file";
   chomp($param1);
   #print $param1;
   #my $testvar="-wWbB";
   system("sar  -o logfile $param1   $interval 0 > /dev/null&");
   exit 0;
  }
  else
  {
  #print "In parent";
  my $exitstatus = wait();
   exit;
  }
}

# stopping sar.....
elsif($ARGV[0] eq 'stop')
{

# Checking for correct parameters.. 
 if (exists $ARGV[1])
 {
   print "Bad parameters cant process\n";
   exit;
 }  
  
  my $loc;
  open FH, "< fileloc" or die " cant open file";
  $loc = <FH> ;
  #print $loc;
  chomp($loc);
  close FH or die "cant close file";
  system("kill \$(pidof sadc)");
  system("sar -f logfile>>$loc");
}

else 
{
  print " Wrong parameters";
}
[download]

Comment on Re^2: Running Perl scripts from ssh Download Code

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Re^3: Running Perl scripts from ssh by Corion (Patriarch) on May 08, 2006 at 11:58 UTC
Part of your script is still running - that's why ssh doesn't terminate the connection: `... my $pid = fork(); ...` [download] You need to detach your child process from the parent process - maybe it's enough to close STDIN and STDOUT, but I'd use Proc::Daemon or what `perldoc -q daemon` says to start the program detached in the background: `use POSIX qw(setsid); close STDIN; close STDOUT; close STDERR; # or better, reopen them into some logfile setsid(); fork && exit; # We are now detached from ssh` [download]	[reply] [d/l] [select]
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Re^3: Running Perl scripts from ssh by blazar (Canon) on May 08, 2006 at 12:56 UTC
`#!/usr/bin/perl -w #exec /usr/bin/perl /research-sar/sarexec.pl use strict;` [download] Good! Just as a suggestion on a minor point, try `#!/usr/bin/perl use strict; use warnings;` [download] `if($ARGV[0] eq 'start') { # Checking for correct parameters.. if (exists $ARGV[1] && exists $ARGV[2] && exists $ARGV[3]) { #print "present all things\n"; } else { #print "Missing parameters..cant continue..\n"; exit; }` [download] In Perl you don't need all those nested conditionals and there are alternatives that may increase readability. In this case you may want to create a `start()` and a `stop()` sub, then I'd do: `my %action=(start => \&start, stop => \&stop); my $todo=shift \|\| ''; die "Wrong parameters\n" unless $action{$todo}; goto $action{$todo}; # a "good" goto; # # ... # sub $start () { die "Missing parameters, can't continue!\n" unless @ARGV==3; my ($file_param,$file_location,$interval)=@ARGV; # ... }` [download] `open(FH,"> fileloc") or die"cant open the file";` [download] open my $fh, '>', 'fileloc' or die "Can't open `fileloc': $!\n"; [download] `my $pid = fork();` [download] Aha! `=>` fork.	[reply] [d/l] [select]