Another question about the split function

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

I an using split to break strings like these:

  Resource Group: gr_shared_fs
      rs_ipaddr (heartbeat::ocf:IPaddr):        Started lapg2-a
      rs_raid1_shared_fs        (heartbeat::ocf:Raid1): Started lapg2-
+a
      rs_fs_shared      (heartbeat::ocf:Filesystem):    Started lapg2-
+a
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into blocks separated by space. Please note the white space in front of the rs_ starting strings (below "Reso" from the first line). That white space may or may not be there. I need to split the strings and I am using this:

my @statusLineFields = split(/\s+/, $statusLine);
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but it seems if I do have that white space there the first element in @statusLineFields is whitespace. If the input lines do not have any leading space then the first element is some rs_ string. I really need to ignore that white space and have the first element be the rs_ string somehow.

I have the feeling this is a 1-line quick and easy answer but I've been running circles around my tail and couldn't figure it. In addition to this, once I split the line, the elements of that array (with or without the first one being whitespace) are surrounded by one blank space on each side. That "Started" is actually " Started ". Why is this and how do I get rid of it?

Thanks!

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Re: Another question about the split function
by FunkyMonk (Chancellor) on Dec 11, 2007 at 23:10 UTC

split

documentation

from the command line by typing perldoc -f split (*nix and Windows)
in HTML (ActivePerl on Windows) via start-->Programs-->ActivePerl-->Documentation
by typing doc://split into the PerlMonks search box
by Googling for perldoc split.

Any of the links I've posted will also take you there.

Anyway, split says (with my emphasis)...

If EXPR is omitted, splits the $_ string. If PATTERN is also omitted, splits on whitespace (after skipping any leading whitespace)

and ...

As a special case, specifying a PATTERN of space (' ' ) will split on white space just as split with no arguments does

my @statusLineFields = split(' ', $statusLine);
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Re^2: Another question about the split function

by pfaut (Priest) on Dec 11, 2007 at 23:16 UTC

If EXPR is omitted, splits the $_ string. If PATTERN is also omitted, splits on whitespace (after skipping any leading whitespace)

As a special case, specifying a PATTERN of space (' ' ) will split on white space just as split with no arguments does

Those little factoids escaped me. I suppose it's time to start reading 'Programming Perl' for the third (or is it fourth?) time. No matter how many times I read it I always pick up something new

90% of every Perl application is already written. ⇒

dragonchild

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Re: Another question about the split function
by pfaut (Priest) on Dec 11, 2007 at 22:53 UTC

Remove the leading spaces before doing the split.

$statusLine =~ s/^\s+//;

90% of every Perl application is already written. ⇒

dragonchild

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Re: Another question about the split function
by Fletch (Bishop) on Dec 11, 2007 at 22:54 UTC

If leading whitespace really isn't significant then why not just remove it before further processing (e.g. $line =~ s/^\s+//;)?

The cake is a lie.
The cake is a lie.
The cake is a lie.

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Re: Another question about the split function
by almut (Canon) on Dec 11, 2007 at 22:57 UTC

Try the magical ' '

my @statusLineFields = split(' ', $statusLine);
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Re: Another question about the split function
by downer (Monk) on Dec 11, 2007 at 23:15 UTC

$_ =~ s/^\s//gm

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