Variables with ssh and awk with perl - linux

Question

Trying to execute remotely a bunch of commands in a perl script
This looks like that :
$CMD1 = "/usr/sbin/mminfo -av -q \"savetime>'-1 day 18:00:00',savetime<'17:59:59'\" -r \"ssid,totalsize,nfiles,pool\"|grep \"xxxxx\"|/usr/bin/awk '!seen[\$1]++'";
print Dumper $CMD1;
$CMD = "/usr/bin/ssh xxxx\#$SRV \'$CMD1\' 2>&1";
print Dumper $CMD;
But I still have problem with the $1 in the awk command, It seems to be cancelled when running.
What I can see :
$VAR1 = '/usr/sbin/mminfo -av -q "savetime>\'-1 day 18:00:00\',savetime<\'17:59:59\'" -r "ssid,totalsize,nfiles,pool"|grep "xxxxxx"|/usr/bin/awk \'!seen[$1]++\'';
$VAR1 = '/usr/bin/ssh xxxxx#\'xxxxxx\' \'/usr/sbin/mminfo -av -q "savetime>\'-1 day 18:00:00\',savetime<\'17:59:59\'" -r "ssid,totalsize,nfiles,pool"|grep "xxxxx"|/usr/bin/awk \'!seen[$1]++\'\' 2>&1';
So the '$1' of the awk command is passed correctly to the remote but when running :
#RESU = `$CMD`;
print Dumper #RESU;
I can see that my $1 is missing (or interpretated by the remote shell as a null value) :
$VAR1 = 'awk: ligne de commande:1: !seen[]++
';
$VAR2 = 'awk: ligne de commande:1: ^ syntax error
';
$VAR3 = 'awk: ligne de commande:1: error: expression indice non valide
';
I've tried many things like quoting or double-quoting the string, creating the string with perl 'qq' function, putting value of $CMD1 directly in $CMD and escaping quotes but no way.
And of course, my awk is piped to another awk (not provided here).
I don't want a solution which runs awk localy since I've millions lines returned from the 'mminfo' command.
Any clue (or a better way to do that !) ?

Answer 1

You might want to break it into smaller pieces for readability, and use the multi-arg invocation of system to avoid perl having to spawn a shell. The q() function goes a long way toward avoiding quoting hell.
$mminfo = q{/usr/sbin/mminfo -av -q "savetime>'-1 day 18:00:00',savetime<'17:59:59'" -r "ssid,totalsize,nfiles,pool"};
$awk = q{/usr/bin/awk '/xxxxx/ && !seen[$1]++');
print Dumper [$mminfo, $awk];
#cmd = ( "/usr/bin/ssh", "xxxx\#$SRV", "$mminfo | $awk" );
print Dumper \#cmd;
system #cmd;

Answer 2

Even if you can not use modules in your final environment, you may be able to use them in your local machine. In that case you can use them to quote the command programmatically and then just copy and paste the quoted string into the script you are developing. For instance:
use strict;
use warnings;
use Net::OpenSSH;
my $quoted_cmd1 = Net::OpenSSH->shell_quote('/usr/sbin/mminfo', '-av',
-q => q(savetime>'-1 day 18:00:00',savetime<'17:59:59'),
-r => 'ssid,totalsize,nfiles,pool',
\\'|',
'grep', 'xxxxx',
\\'|',
'/usr/bin/awk', '!seen[$1]++');
my $SRV = "foo";
my $quoted_cmd = Net::OpenSSH->shell_quote('/usr/bin/ssh', "xxxx\#$SRV",
$quoted_cmd1,
\\'2>&1');
print "$quoted_cmd\n";
Which outputs...
/usr/bin/ssh xxxx#foo '/usr/sbin/mminfo -av -q '\''savetime>'\''\'"''"'-1 day 18:00:00'\''\'"''"',savetime<'\''\'\''17:59:59\'\'' -r ssid,totalsize,nfiles,pool | grep xxxxx | /usr/bin/awk '\''!seen[$1]++'\' 2>&1