chomp removes everything *except* the newline?

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

I'm going insane, right? Trying to trim newlines out of an array read from a file. I'm a relative newb, but everything I've read on the internet tells me this should work. (I've taken out all the format validation for testing).

input.txt has this in it:

111.111.111.111
222.222.222.222
333.333.333.333
[download]

Here is my snippet:

my $File = input.txt;
open(FILE, "$File");
@IPLIST = <FILE>;
close(FILE);

foreach my $test (@IPLIST) {
  print "Is $test an IP?\n";
}
[download]

Output looks like this:

Is 111.111.111.111
an IP?
Is 222.222.222.222
an IP?
Is 222.222.222.222
an IP?
[download]

Expected behavior, right? So then I add chomp(@IPLIST); before my loop, and the output becomes this:

Is
an IP?
Is
an IP?
Is
an IP?
[download]

Same behavior if I do it on the read: chomp( @IPLIST = <FILE> ); or in the loop for each element. Isn't chomp supposed to do the opposite of this??? What am I missing?

Comment on chomp removes everything except the newline? Select or Download Code

Replies are listed 'Best First'.
Re: chomp removes everything except the newline? by Anonymous Monk on Jun 26, 2010 at 17:33 UTC
When your code is made runnable (see below), it works fine. Be sure to use strictures (the strict, warnings, and maybe diagnostics pragmas) to catch syntax errors and such. `#!perl use strict; use warnings; my $File = "input.txt"; # this string wasn't quoted, so you must have +not shown us the code you're using open(FILE, "<", $File) or die qq(failed to open file "$File": $!); # y +ou didn't check whether open failed chomp(my @IPLIST = <FILE>); # this works as expected close(FILE); foreach my $test (@IPLIST) { print "Is $test an IP?\n"; }` [download] Output: Is 111.111.111.111 an IP? Is 222.222.222.222 an IP? Is 333.333.333.333 an IP?	[reply] [d/l]
Re^2: chomp removes everything except the newline? by follier (Initiate) on Jun 26, 2010 at 18:41 UTC
Thanks for your help. Sorry about the inaccuracy but I hand-typed the code in my post and missed the quotes. Anyhoo, it is working now that I changed `open(FILE, "$File")` to `open(FILE, "<", "$File")`. I have no idea how reading the file without that "<" could have affected chomp later o_O	[reply] [d/l] [select]
Re^3: chomp removes everything except the newline? by almut (Canon) on Jun 26, 2010 at 18:56 UTC
On a side note, there's no need to put double quotes around `$File`. While this makes sense in shell programming, for when the string has spaces in it etc., in Perl it's plain superfluous.	[reply] [d/l]
Re^3: chomp removes everything except the newline? by GrandFather (Saint) on Jun 26, 2010 at 21:50 UTC
Sorry about the inaccuracy but I hand-typed the code Copy and paste is your friend. If you don't want to post the code you ran, at least run the code you post! it is working now that I changed `open(FILE, "$File")` to `open(FILE, "<", "$File")` That's a start, but one of the mantras around here is: "Always use strictures (use strict; use warnings; - see The strictures, according to Seuss), always use the three parameter version of open, always use lexical file handles and always check the result of I/O". Taking all that on board your open should have looked more like: `open my $inFile, '<', $file or die "Failed to open $file: $!";` [download] Although that doesn't at all explain the chomp oddity you saw. More likely reasons for that behaviour are that you were reading a file generated with different line endings than are native on your OS or something had messed with $/ (see perlvar $/). True laziness is hard work	[reply] [d/l] [select]
Re: chomp removes everything except the newline? by Anonymous Monk on Jun 26, 2010 at 17:29 UTC
Add `use autodie;` and you should see `Can't open 'inputtxt' for reading: 'No such file or directory' at junk +.pl line 3` [download] Use strict warnings and diagnostics or die	[reply] [d/l] [select]
Re: chomp removes everything except the newline? by ikegami (Patriarch) on Jun 27, 2010 at 07:37 UTC
So then I add chomp(@IPLIST); before my loop, and the output becomes this: Then the file probably contained `111.111.111.111<something><NL> 222.222.222.222<something><NL>` [download] where `<something>` is interpreted by the terminal as some sort of command sequence.	[reply] [d/l] [select]