Text filer and assign

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

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Re: Text filer and assign by karlgoethebier (Abbot) on Oct 06, 2015 at 11:38 UTC
`print join ' ', (split /\s/, $line)[1, 9, 10, 11, 12, 13, 14];` Much simpler. Regards, Karl ŤThe Crux of the Biscuit is the Apostropheť	[reply] [d/l]
Re^2: Text filer and assign by RonW (Parson) on Oct 06, 2015 at 23:17 UTC
or: `print join ' ', (split /\s/, $line)[1, 9 .. 14];`	[reply] [d/l]
Re^3: Text filer and assign by karlgoethebier (Abbot) on Oct 07, 2015 at 10:30 UTC
I swear that i dreamed last night that i forgot this... Best regards, Karl ŤThe Crux of the Biscuit is the Apostropheť	[reply]
Re: Text filer and assign by Anonymous Monk on Oct 06, 2015 at 08:15 UTC
I did write a regex code which is not working for me. Please assist. Thanks Please show the code you have written, its easier to help that way	[reply]
Re^2: Text filer and assign by intoperl (Acolyte) on Oct 06, 2015 at 08:22 UTC
code snippet is below : `#!/usr/bin/perl -w use strict; system("pvscan>>pv.txt1"); open my $FH,"pv.txt1" or die "Cannot open file: $!"; while(my $line = <$FH>){ my $pvname = $line =~ /\[\d+\.\d+\sGB\s\/\s\d+\.\d+\sGB\]/i; print $pvname; }` [download] i want the assignment to look like : `pvname = [557.62 GB / 20.50 GB free]` [download]	[reply] [d/l] [select]
Re^3: Text filer and assign by Corion (Patriarch) on Oct 06, 2015 at 08:27 UTC
Most likely, you want to use "capturing" (see perlre) to keep the stuff that interests you: `... if( $line =~ /(\[\d+\.\d+\sGB\s\/\s\d+\.\d+\sGB\])/i ) { my $pvname = $1; print $pvname; };` [download] Note that your regular expression does not match the result you want, because your result has the string `free` in it, while your regular expression will not match that. You should add the string at the appropriate place. While it makes debugging easier, you don't need a temp file: for my $line (`pvscan`) { ... }; [download]	[reply] [d/l] [select]
Re^3: Text filTer and assign - regex tools by Discipulus (Canon) on Oct 06, 2015 at 08:36 UTC
I humly think you need a regex playfield: as usual i suggest two tools: Davido's precious regex tester is now online here the regex coach program I find also YAPE::Regex::Explain useful: >perl -MYAPE::Regex::Explain -e " print YAPE::Regex::Explain->new(qr/\ +[\d+\.\d+\sGB\s\/\s\d+\.\d+\sGB\]/i)->explain();" The regular expression: (?i-msx:\[\d+\.\d+\sGB\s/\s\d+\.\d+\sGB\]) matches as follows: NODE EXPLANATION ---------------------------------------------------------------------- (?i-msx: group, but do not capture (case-insensitive) (with ^ and $ matching normally) (with . not matching \n) (matching whitespace and # normally): ---------------------------------------------------------------------- \[ '[' ---------------------------------------------------------------------- \d+ digits (0-9) (1 or more times (matching the most amount possible)) ---------------------------------------------------------------------- \. '.' ---------------------------------------------------------------------- \d+ digits (0-9) (1 or more times (matching the most amount possible)) ---------------------------------------------------------------------- \s whitespace (\n, \r, \t, \f, and " ") ---------------------------------------------------------------------- GB 'GB' ---------------------------------------------------------------------- \s whitespace (\n, \r, \t, \f, and " ") ---------------------------------------------------------------------- / '/' ---------------------------------------------------------------------- \s whitespace (\n, \r, \t, \f, and " ") ---------------------------------------------------------------------- \d+ digits (0-9) (1 or more times (matching the most amount possible)) ---------------------------------------------------------------------- \. '.' ---------------------------------------------------------------------- \d+ digits (0-9) (1 or more times (matching the most amount possible)) ---------------------------------------------------------------------- \s whitespace (\n, \r, \t, \f, and " ") ---------------------------------------------------------------------- GB 'GB' ---------------------------------------------------------------------- \] ']' ---------------------------------------------------------------------- ) end of grouping ---------------------------------------------------------------------- [download] HtH L* There are no rules, there are no thumbs.. Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.	[reply] [d/l]
Re^3: Text filer and assign by johngg (Canon) on Oct 06, 2015 at 13:23 UTC
`system("pvscan>>pv.txt1"); open my $FH,"pv.txt1" or die "Cannot open file: $!";` [download] I see that you append to the `pv.txt1` file which means more lines to parse every time you run the script; is this actually intended? Unless you want to keep the output of `pvscan` hanging around you can open a file handle directly on piped commands. Something like:- `open my $pvscanFH, '-\|', 'pvscan' or die "Cannot fork pvscan: $!\n";` [download] You can then read the command output line by line just as if it was a file on disk. I hope this is helpful. Cheers, JohnGG	[reply] [d/l] [select]