Manipulating Output

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

I need to find out how to get an output from a file with a : delimeter. I want to just get the Server name here.

So my output right now is:

222.222.333.444:firstServer
121.222.222.222:secondServer
[download]

I would like it to be:

firstServer
secondServer
[download]

here is my script as of now:

@a = (<DATA>);
$file = "bas.txt";
foreach (@a)
{
       open(FILE,">>$file") || die "Can't open $file: $! \n";
       print FILE "$_\n";
}             
close(FILE);
close(DATA);

__DATA__
222.222.333.444:firstServer
121.222.222.222:secondServer
[download]

Comment on Manipulating Output Select or Download Code

Replies are listed 'Best First'.
Re: Manipulating Output by Abigail-II (Bishop) on Jul 09, 2002 at 14:34 UTC
`print FILE (split /:/ => $_) [-1], "\n";` [download] Question: why do you open the file in each iteration? Opening it once is more efficient. Abigail	[reply] [d/l]
Re: Re: Manipulating Output by Anonymous Monk on Jul 09, 2002 at 15:32 UTC
thanks. Sorry I only gave just a small portion of my script and you answered my question. Now that it works can you please explain how this works???? I am lost on the `=>` and the `[-1]` parts. `print FILE (split /:/ => $_) [-1], "\n";` [download]	[reply] [d/l] [select]
Re: Manipulating Output by Abigail-II (Bishop) on Jul 09, 2002 at 15:34 UTC
`=>` is a fancy comma, and `[-1]` takes the last element of the list preceeding it. Abigail	[reply] [d/l] [select]
Re: Re: Manipulating Output by Anonymous Monk on Jul 09, 2002 at 15:43 UTC
Re: Manipulating Output by ehdonhon (Curate) on Jul 09, 2002 at 15:00 UTC
Abigail-II has the correct perl solution. However, if all you are doing is writing a very small perl program for that purpose alone, there's no need to re-invent the wheel. `cut -f 2 -d ':' data_file > output_file` [download]	[reply] [d/l]
Re: Manipulating Output by Abigail-II (Bishop) on Jul 09, 2002 at 15:12 UTC
Or a perl one-liner: `perl -aF: -ple'$_=pop@F' in_file > out_file` [download] Abigail	[reply] [d/l]
Re: Re: Manipulating Output by redsquirrel (Hermit) on Jul 09, 2002 at 15:12 UTC
Here are a few ways to do it if you want to do it from the command line in Perl: `perl -pe 's/[^:]+://' data_file > output_file perl -nle 'print /([^:]+)$/' data_file > output_file perl -nle 'print+(split /:/)[-1]' data_file > output_file` [download] TMTOWTDI, --Dave	[reply] [d/l]
(zdog) Re: Manipulating Output by zdog (Priest) on Jul 09, 2002 at 15:56 UTC
Here are a few comments on your existing code: `use strict; # always 'use strict' use warnings; # always 'use warnings' or the -w switch chomp (my @a = <DATA>); # chomp the array to get rid of extra \n's my $file = "bas.txt"; # get the open() out of the loop so it's not repeated unnecessarily open (FILE, ">>$file") \|\| die "Can't open $file: $! \n"; print FILE "$_\n" for @a; # shorter; sweeter close(FILE); close(DATA); __DATA__ 222.222.333.444:firstServer 121.222.222.222:secondServer` [download] I know that I'm not answering your question (it's been done), but those are a few other things to keep in mind for the future. Zenon Zabinski \| zdog \| zdog@perlmonk.org	[reply] [d/l]
Re: Manipulating Output by hiseldl (Priest) on Jul 09, 2002 at 15:16 UTC
if the data file exists and you want to keep the same filename (this will keep the original with .bak suffix): `> perl -pi.bak -e "s/^.://" data.txt` [download] or if you would like to create a new file to hold the output: `> perl -pe "s/^.://" data.txt > output.txt` [download] -- .dave.	[reply] [d/l] [select]


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