reading from a file into an array in perl

[Sooraj S]

Hi,

I want to read all the data from a file into an array. But if there
is any "#" character in the file it should be replaced with "&"
character. How to store "$_" into an array?

This is my code:
my @tmp_arr;
open(IN,"<./ip_file");
while(<IN>)
{
if(/#/)
{
s/#/&/g;
}
-------------- //add ur code here
}
close(IN);
foreach(@tmp_arr)
{
print "$_";
}

 

[Justin C]

Hi,

I want to read all the data from a file into an array. But if there
is any "#" character in the file it should be replaced with "&"
character. How to store "$_" into an array?

This is my code:
my @tmp_arr;
open(IN,"<./ip_file");
while(<IN>)
{
if(/#/)
{
s/#/&/g;
}
-------------- //add ur code here
}
close(IN);
foreach(@tmp_arr)
{
print "$_";
}

I think you need <URL:http://oreilly.com/catalog/9780596001322>

Also, that 'if' is redundant. Just s/#/&/g without the 'if' around it,
if there isn't a '#' then there is no match and therefore no substitu-
tion.

There are a few other things that, around these parts at least, are
considered bad practice (and who am I to argue?), but, considering the
nature of the problem you have, I don't think it beneficial to point
them all out, but to suggest you read the book mentioned above.

Justin.

 

[Peter Valdemar Mørch]

        --------------                            //add ur code here}

Is this what you're looking for?

push @tmp_arr, $_;

Peter

 

[Jürgen Exner]

I want to read all the data from a file into an array.

@arr = <$F>;

Or use File::Slurp

But if there
is any "#" character in the file it should be replaced with "&"
character.

AFAIR # isn't special in REs, so a simple
s/#/&/g;
should do. Or
tr/#/&/;

How to store "$_" into an array?

You assign the value of $_ to whatever position in the array you want
$arr[123] = $_;

This is my code:

my @tmp_arr;
open(IN,"<./ip_file");

You should use lexical file handles.
You should use the three-argument for of open()
You should always check for success of open()

open ($IN, '<', './ip_file') or die "Cannot open ./ip_file: $!";

while(<IN>)
{
if(/#/)
{
s/#/&/g;

There is no reason to hide the s/// inside of an if(). If there is no #
then the s/// just won't do anything anyway.

}
-------------- //add ur code here
}
close(IN);
foreach(@tmp_arr)

Where is this array coming from? You never declared it (are you using
warnings and strictures? You absolutely should!!!) and never defined it,
therefore it is empty and this loop will never be executed.

{
print "$_";

Please read "perldoc -q quoting":
What's wrong with always quoting "$vars"?

jue

 

[Peter Valdemar Mørch]

Where is this array coming from? You never declared it (are you using
warnings and strictures? You absolutely should!!!) and never defined it,
therefore it is empty and this loop will never be executed.

Uhm, didn't he in fact declare it explicitly?:

This is my code:
my @tmp_arr;
bla bla

Peter

 

[Jürgen Exner]

Uhm, didn't he in fact declare it explicitly?:

You are right, sorry.
Still, he doesn't put any values in it.

jue