More interesting q's.... 1

[vptl]

Morning all,
Yes me again...still long way to go....I did tried to figure it out..but got no where...
Here is what I want to do.
I am doing in a while loop.
while ( $fs = <FS_LIST> ) {
chomp ($fs);
$line=`/nas/bin/fs_replicate -info $fs |egrep current_delta` ;
print "$fs.$line\n" ;
}
close (FS_LIST);


My command output is
<text1> = <Number1>
<text2> = <Number2>

for each $fs. Also for some $fs output is blank line.
I want to attach my $fs to each of the output line. Since I have two line output, $line is asssingmed only to entire string. and I get...
$fs.<text1> = <Number1>
<text2> = <Number2>

I am following O'Relly book (Learning Perl.) ,I saw example for %word which has only 2 clmns. in my case I have 3 clmns.

Thanks,

 

[vptl]

Here is what I am in looking into...
$line=system(qq!/nas/bin/fs_replicate -info $fs |egrep current_delta|sed s/\$/$fs/) ;

 

[TrojanWarBlade]

You probably want to assign the result of the backticks to an array instead of a scalar and then print that out.

my @lines = `/nas/bin/fs_replicate -info $fs |egrep current_delta`;
foreach my $line (@lines) {
  print "$fs.$line\n";
}

Try that and see what happens.


Trojan

 

[vptl]

Trojan,
Thanks...This works..if you do not mide can you please educate me...
1. "my" is it s std perl requirement to define array ?
b/c I saw example in the book which just says
@words = qw( x1,x2,x3) ;

2.when you use foreach my $lines (@lines)
is "my $lines" is the name of the array ?

3. @lines (in #2) is same is starting from 0,1,2..$ ?
like $line[0] ,$line[1]...and so on?

4. Please see why I cannot do this...
$line1=`/nas/bin/fs_replicate -info $fs |egrep current_delta|sed s/\$/_$fs/`;
if ( $line1 eq '' ) {
print "$fs IS NOT REPLICATING\n" ;
} else {
@info = qw("$line1") ;
print "$info[0]\n";
print "$info[1]\n";
print "$info[2]\n";
print "$info[3]\n";
}
#IMPmy @lines = `fs_replicate -info $fs |egrep 'current_delta|Error'`;
#IMPforeach my $lines (@lines) {
#IMPprint "$fs.$lines\n";
#IMP}
}
close (FS_LIST);

I get error in printing $info[0] and all of them...

I know so many questions..again....I am going to do this...until I know perl.! Thank you very much for you kind support.

 

[vptl]

This is the error I get....FS_LIST is my FileHndl
Use of uninitialized value in concatenation (.) at /tmp/nas_mon line 28, <FS_LIST> line 2.

 

[TrojanWarBlade]

Crikey!
What a lot of questions :-S

1. "my" is a means of "scoping" a variable. It causes the variable scope to be limited (in simple terms at least) to the surrounding curly braces ("{" and "}").

2. the "my $line" creates a pseudo reference to each element of the array "@lines" in turn.

3. Nearly, watch the "s". It walks through the array "@lines" as you suggest but each element of the array is "$lines[0]" and "$lines[1]" etc, not "$line[0]".

4. Sorry, not sure what you're trying to do here and I don't have time at the moment to look into it. I might get a moment later if no-one returns to you in the mean while.

Trojan

 

[vptl]

thanks.
just to let uou know what I am trying to do is assign each element of the output to a array variable so that I can test them as I need.
so like I mentioned earlier...my o/p is
<text1> = <Number1>
so array[1]=<text1>
array[2]="="
array[3]=<Number1>
while I am writing this..I think my second elect "=" is causing prob..I will chk.
No rush, when you have time...I know for you it will be...less then 1 min....

 

[TrojanWarBlade]

my $sample_string = "<text1> = <Number1>";
my @parts = split /\s/, $sample_string, -1;



Trojan.

 

[vptl]

I have my $line variable as

"current_delta_set 4410_fs1
current_delta_set 4409_fs1"

What I want is I want
info[1]=current_delta_set
info[2]=4410_fs1
info[3]=current_delta_set
info[4]=4409_fs1

 

[TrojanWarBlade]

ok,

push @info, split(/\s+/, $line, -1);

Trojan.

 

[vptl]

Bingo !
Thank you very much sir...I think I am almost there...
Great stuff....Your PERL knowledge is very impressive.
BTW...(I cannot let you go w/o asking anything...lastone for today..promiss.) What is -1 for ?

 

[vptl]

This is my final script....
Still one problem...(for tomorrow.)
my while loop is not working...first I get $fs=fs1 and it stays there..!

Only and when you have some time....

#!/usr/bin/perl -w
system(q!/nas/bin/nas_fs -list | egrep -v 'root|name' | awk '{print $6}'|sed '/^$/d' > /tmp/fs_list!);
open (FS_LIST,"fs_list") ;
while ($fs=<FS_LIST>) {
chomp ($fs);
print "$fs\n";
$line=`/nas/bin/fs_replicate -info $fs |egrep current_delta|awk -F"=" '{print \$1,\$2}'|sed s/\$/_$fs/`;
chomp($line1);
if ( $line eq '' ) {
print "$fs IS NOT REPLICATING\n" ;
} else {
push @info, split(/\s+/, $line, -1);
print "$info[1]\n";
print "$info[3]\n";
}
print "$fs\n";
}
close (FS_LIST);

Thanks.

 

[vptl]

Got it.....the magic teaching.....
qq to interpret $fs.....
Will always remember you sir.

 

[TrojanWarBlade]

Now you're starting to really learn.
Enough to be able to work stuff out for yourself. It gets better and easier from here on.
BTW: I still think that you need to consider replacing your "system" functions and getting perl to do all the work.
I don't know what "/nas/bin/nas_fs" does and I guess you may have to keep that but certainly you could replace any greps awks and seds with simple perl regex's.

Trojan.

 

[stevexff]

As Trojan says, shelling out to sed and awk may be convenient, but future maintainers of your script need to know three languages instead of one.

Suggested design: Lose the temporary files altogether.

use strict;
use warnings;

my @fslist = qx[/nas/bin/fs_replicate -info];
chomp @fslist;

foreach my $fs (@fslist) {
   next unless $fs =~ /root|name/;
   ...
}

Also, look up the obscure options and switches for the fs_* commands in the manual. Many command-line utilities have options to suppress headers and blank lines in their output to make scripting easier. It might save you a lot of hassle parsing the output, when you don't need to.

 

[vptl]

Trojan thanks for your kind words......And yes...you are my teacher....

Thanks to Steve also for his input in this regard.
I know all of you are doing this great work along with full time job.This is a great help for so many of my like,which is really beyond something normal people do.

What is qx ? what is "use strict " and "use warnings" do in the script....please do not mind I am still doing my first chapter....

Thanks.
V

 

[TrojanWarBlade]

qx" is similar to "qq" and "q". "q" allows you to define your own single quotes, "qq" double quotes and "qx" backticks.
When you use a character that is part of a pair (such as square or round brackets), the closing character would be the other of that pair (makes things look neater).

"use strict;" and "use warnings;" should really always be used to protect yourself from silly mistakes.
"use strict;" requires that you pre-delare all variables with "my" before you use them (or that you fully declare the package for a global variable wherever you use it). That might sound like a pain but it stop most typo errors.
You could also try "use diagnostics;" which is very useful for a beginner. When in force and an error occurs, it tries to explain in great detail what might have gone wrong and how to fix it.

What more could you ask for?!!! ;-)

Trojan.

 

[vptl]

Thank you sir.