chomp a List

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

Newbie here
I'm having a problem with the returned list of files of my directory
how do I remove the last comma from my list
I know it involves chomp but I can't seem to get it right
---code---

use Cwd;
my $dir = getcwd;

opendir (DIR, $dir) or die $!;
my @dir = readdir DIR;

foreach my $item (@dir) {

print "$item," if -r $item and -w $item and -x $item and $item =~ /^[a
+-zA-Z]/ ;         # Readable and not writable

}
[download]

---end code---
any help is greatly appreciated
thanks
pcadv

20040208 Edit by ysth: code tags

Comment on chomp a List Download Code

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Re: chomp a List by blokhead (Monsignor) on Feb 07, 2005 at 22:01 UTC
You cannot use chomp to erase characters you have already printed. For the logic of separating items by commas, Perl has the convenient join function. All you need to do is get the items you want to print into a list to pass to join. grep is a good way to do this: `my @dir = readdir DIR; my @to_print = grep { -r $_ && -w $_ && -x $_ && /^[a-zA-Z]/ } @dir; print join "," => @to_print;` [download] blokhead	[reply] [d/l]
Re^2: chomp a List by ZlR (Chaplain) on Feb 08, 2005 at 09:26 UTC
`print join "," => @to_print;` [download] I never saw this ! Does this means that one can use => instead of a coma everywhere ? Is there a precedence difference ? I'm used to do : `print join(",", @to_print)` [download] which is obviously less idiomatic .	[reply] [d/l] [select]
Re^3: chomp a List by tirwhan (Abbot) on Feb 08, 2005 at 12:12 UTC
=> is almost the same as , The difference is that => forces the value to the left of it to be interpreted as a quoted string This is why `#!/usr/bin/perl -w my %a=( foo => "bar", fi , "fo");` [download] Will get you a warning for the unquoted fi, but not the unquoted foo. However, normal operator precedence still applies, so `print join , => @to_print;` [download] won't work, whereas `print join or => @to_print;` [download] will.	[reply] [d/l] [select]
Re^4: chomp a List by ZlR (Chaplain) on Feb 08, 2005 at 12:40 UTC
Re^2: chomp a List by Anonymous Monk on Feb 08, 2005 at 15:57 UTC
Thank you for the help its almost to simple.	[reply]
Re: chomp a List by cog (Parson) on Feb 07, 2005 at 23:20 UTC
Not that I recommend it, but you could `print "\b"` in the end. Still, blokhead's suggestion is better :-) I just wanted to point that there is more than one way to do it :-)	[reply] [d/l]
Re: chomp a List by sh1tn (Priest) on Feb 08, 2005 at 00:06 UTC
Not so elegant way: `... my $coutnter; for( @dir ){ print $_; $counter++; print ',' unless $counter == @dir; } ...` [download]	[reply] [d/l]