remove 16 Zeros

eghdam has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: remove 16 Zeros by flexvault (Monsignor) on Oct 13, 2015 at 09:23 UTC
eghdam, if you know that the 'pvid' is always 32 characters then: `my $pvid = "00c1be9a467335ce0000000000000000"; my $newpvid = substr( $pvid, 0, 16 ); print "\$newpvid: $newpvid\n";` [download] but also reading some more documentation wouldn't hurt! Regards...Ed "Well done is better than well said." - Benjamin Franklin	[reply] [d/l]
Re^2: remove 16 Zeros by eghdam (Initiate) on Oct 13, 2015 at 11:49 UTC
Hi! Yes thank u for Response. PVID is allways 32 Charachters. My Script is: @output =`command` # Output looks like 7 lines and on line is the pvid: pvid 00c1be9a467335ce0000000000000000 foreach $line (@output) { if ($line =~ /pvid ..... here i want to grep only the 32 charachters $pvid = $1 } i just want to get the $pvid.	[reply]
Re^3: remove 16 Zeros by flexvault (Monsignor) on Oct 13, 2015 at 20:32 UTC
eghdam, Why make it so complicated ( however it is your script :-) ############# UNTESTED ################ use strict; my $pvid = ''; # initialize my @output = `command`; # Output looks like 7 lines and on [one] li +ne is the pvid: # pvid 00c1be9a467335ce0000000000000000 # I use qx/command/; # easier to see in cod +e for me! foreach my $line ( @output ) { # print "$line\n"; ## If not working, use print to figure out w +hat's happening if ( substr( $line, 0, 5 ) eq 'pvid ' ) { $pvid = substr( $line, 6, 16 ) # or '32' as you require last; } } if ( $pvid eq '' ) { ... } ## Generate warning or do some error h +andling! [download] I'm coding to my style, but you are free to chose what works for you. But remember if you have to go back to the code and update, make it as easy to understand as possible. Don't spend 2 hours figuring out what you did and then make a 2 line update. Good Luck...Ed "Well done is better than well said." - Benjamin Franklin	[reply] [d/l]
Re: remove 16 Zeros by mr_ron (Chaplain) on Oct 13, 2015 at 14:34 UTC
Perl regular expressions can count as explained in perlretut - Perl regular expressions tutorial in the section on on matching repetitions. So /0{16}/ matches exactly 16 zeroes. `use strict; use warnings; my $line = "pvid 00c1be9a467335ce0000000000000000"; my $pvid; if ($line =~ /pvid\s+(.)0{16}$/) { $pvid = $1 } print "$pvid\n"; __END__ 00c1be9a467335ce` [download] Since the string you are trying to extract consists of hex digits, a slight improvement on the regex might be: `/pvid\s+([[:xdigit:]])0{16}$/` . Go to perldoc.perl.org and search for "character class" to learn more ... Ron	[reply] [d/l] [select]
Re^2: remove 16 Zeros by Anonymous Monk on Oct 14, 2015 at 06:46 UTC
Oh yeah. that works fine. I have to find out about 1000 PVID's from DISKS. So i list DISKS and read the Configuration of DISK's, where i must grep the string pvid and filter only he pvid. So this is the better solution. thank u Ron :-)	[reply]
Re: remove 16 Zeros by ww (Archbishop) on Oct 13, 2015 at 12:20 UTC
Frankly, I find your question hard to understand... and not just because you failed to use proper markup -- i.e., code tags (<c> ... </c>) around data and code. Please see the markup instructions at the text entry box or read Writeup Formatting Tips). But addressing what I surmise you may think is a partial approach to your problem (including the possibility of a variable char count before your 16 zeros), the following should do the job: `#! /usr/bin/perl -w use strict; # 1144651 my $pvid; my $line = "pvid 00c1be9a467335ce0000000000000000"; if ($line =~ /(pvid .?)0000000000000000$/ ) { $pvid = $1; } print $pvid;` [download] Your "partial approach" " `if ($line =~ /pvid\+(.$)s{0000000000000000}{ $pvid = $1 }`" provides no mechanism to capture the initial four chars, "pvid", nor any limitation on how many times to accept what the dot represents (a single instance of anything, char, num, symbol....). In a regex, the "`$`" marks the end of an input line, so an input with additional data -- if you had any limit on the `.` (anything, any number of times) -- would never match. Then -- as written -- your curly braces enclosing the zeros are a quantifier for how many times to match `"s"` Finally, you don't terminate the "partial approach's" regex with a closing slash, "`/`". As a prophet once said, you can't just make stuff up and expect the computer to understand. Note also the "`my $pvid` which makes the variable global, and allows perl to pass its content back to the code outside the `if` clause. As others observed, best you read docs such as `perldoc perlre` and `perldoc perlretut`... available at your own console... and perhaps tutorials (Tutorials) here such as Getting Started with Perl. Updated:* textual typos corrected and formatting changed for readability. Spirit of the Monastery	[reply] [d/l] [select]
Re^2: remove 16 Zeros by eghdam (Initiate) on Oct 13, 2015 at 12:46 UTC
thank u very much. I am just in Process to get to manual. again thank u.	[reply]
Re^3: remove 16 Zeros by RonW (Parson) on Oct 14, 2015 at 15:06 UTC
Your installation of Perl includes a "manual". Use the `perldoc` command to access it. Also, all of the "official" Perl documentation is available online at http://perldoc.perl.org	[reply] [d/l]
Re: remove 16 Zeros by Anonymous Monk on Oct 13, 2015 at 08:55 UTC
See perlintro#Simple substitution `s{0000000000000000}{}; ## remove 16 zeros` [download]	[reply] [d/l]
Re^2: remove 16 Zeros by Anonymous Monk on Oct 15, 2015 at 20:32 UTC
So cool!	[reply]
Re^3: remove 16 Zeros by Anonymous Monk on Oct 21, 2015 at 06:58 UTC
Folk, i need help again :-( how do i save this value (pvid) to a sub function in perl? there are keys defined in the sub function and they are pushed and later prints in html: `push(@{$lsmap_slots{$key}}, $svsa); push(@{$lsmap_slots{$key}}, $physloc); push(@{$lsmap_slots{$key}}, $vtd); push(@{$lsmap_slots{$key}}, $lun); push(@{$lsmap_slots{$key}}, $backing); push(@{$lsmap_slots{$key}}, $bdphysloc); push(@{$lsmap_slots{$key}}, $status);` [download] how do i push pvid in this sub function?> i know, i have to read but Perl is very heavy for me at the Moment. Kind Regards	[reply] [d/l]
Re^4: remove 16 Zeros by Anonymous Monk on Oct 21, 2015 at 07:11 UTC
Re^5: remove 16 Zeros by Anonymous Monk on Oct 26, 2015 at 10:52 UTC