Can't / won't print pipe delimiter?

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

Memographic Monks,

I have

@my_list = (3, 5, 2, 9);

for $i (0 ..$#my_list) {
   print $my_list[$i]."|";
}
[download]

outputs

3529
[download]

If I change the print to

   print $my_list[$i]."XX";
[download]

it outputs

3XX5XX2XX9XX
[download]

If I change it to

   print $my_list[$i]."|n";
[download]

it outputs

3|n5|n2|n9|n
[download]

But it will not output

3|5|2|9|
[download]

as I want. Not even if I try

   print $my_list[$i]."\|";
[download]

I know, pipe, perl control character....what's the trick to get it to print what I want?

Thanks.

UPDATE

Aie - holiday Monday programming - ok, time to take my lumps -

the code I provided was a short form for the real code which was

@my_list = (3, 5, 2, 9);

for $i (0 ..$#my_list) {
   ... a bunch of stuff...

   $my_id_list .= $my_list[$i]."|";

   ... a bunch more stuff...
}
print $my_id_list;
[download]

where more scanning the code revealed this helpful little line

#trim trailing delimiter
$my_id_list =~ s/\|$//;
[download]

in ...a bunch more stuff..., which of course was the wrong place for it. Should'a been after the lop and before the print.

So, lessons #3,673,592 & #3,673,593: don't code half asleep on a holiday Monday; post real code or at least a sanitized version of it, not shortcuts.

Let the flagellation begin.

Time flies like an arrow. Fruit flies like a banana.

Comment on Can't / won't print pipe delimiter? Select or Download Code

Replies are listed 'Best First'.
Re: Can't / won't print pipe delimiter? by Old_Gray_Bear (Bishop) on May 18, 2009 at 16:42 UTC
Try `print join('\|',@my_list);` [download] ---- I Go Back to Sleep, Now. OGB	[reply] [d/l]
Re^2: Can't / won't print pipe delimiter? by Marshall (Canon) on May 18, 2009 at 21:39 UTC
Almost perfect! just need one final \| to get output requested. `#!/usr/bin/perl -w use strict; my @list = (3, 5, 2, 9); print join('\|',@list),'\|'; #prints: 3\|5\|2\|9\|` [download]	[reply] [d/l]
Re^2: Can't / won't print pipe delimiter? by Anonymous Monk on May 18, 2009 at 16:51 UTC
`print join "\x7c", @my_list; # :D print join chr 124, @my_list; # :D` [download]	[reply] [d/l]
Re: Can't / won't print pipe delimiter? by talexb (Chancellor) on May 18, 2009 at 17:45 UTC
I would just have used `map` to make that a lot more simple: `print map { "$_\|" } @my_list` [download] And a design pattern that you should start to recognize is that as soon as you see the concatenation operator, you should be thinking about changing that to a list. So `$my_id_list .= $my_list[$i]."\|";` [download] should change to `push ( @my_id, "$my_list[$i]\|" );` [download] Later, after you're done with the loop, you can `join` all of the list elements together. And if your code also removes the last "\|" from the strong that you're building, then you can do `push ( @my_id, $my_list[$i] );` [download] during the loop and `join('\|',@my_id);` [download] at the end of the loop to get the same result. Alex / talexb / Toronto "Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds	[reply] [d/l] [select]
Re^2: Can't / won't print pipe delimiter? by punch_card_don (Curate) on May 18, 2009 at 18:39 UTC
Create an array, multiple pushes, then a join, instead of multiple appends and a regex - - - ya, it certainly codes cleaner. Aren't you supposed to be in the backyard barbecuing?	[reply]
Re^3: Can't / won't print pipe delimiter? by talexb (Chancellor) on May 18, 2009 at 21:04 UTC
Aren't you supposed to be in the backyard barbecuing? Just came back from a nice long bike ride. The steaks are defrosting on the counter. Red wine is open. Grill at 6pm, then .. hockey's on at 730pm. Happy May 24!! Alex / talexb / Toronto "Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds	[reply]
Re: Can't / won't print pipe delimiter? by BrowserUk (Patriarch) on May 18, 2009 at 16:40 UTC
But it will not output `3\|5\|2\|9\|` Works for me? `c:\test>perl @my_list = (3, 5, 2, 9); for $i (0 ..$#my_list) { print $my_list[$i]."\|"; } ^Z 3\|5\|2\|9\|` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply] [d/l] [select]
Re: Can't / won't print pipe delimiter? by Anonymous Monk on May 18, 2009 at 16:38 UTC
How are you running this program? Your shell is probably interfering, because \| is not a control character	[reply]
Re: Can't / won't print pipe delimiter? by artist (Parson) on May 18, 2009 at 16:39 UTC
It prints perfectly fine on my machine with "\|". I am not sure, why you don't get that. Try '\|' rather than "\|". Also mention which version of perl you are using. --Artist	[reply] [d/l]
Re^2: Can't / won't print pipe delimiter? by chromatic (Archbishop) on May 18, 2009 at 21:14 UTC
Try '\|' rather than "\|". What would you expect that to do? Are you thinking of the pattern to split? Even in that case, it wouldn't matter -- the pipe character has no special interpolation properties in single- versus double-quoted strings.	[reply]


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