Read line by line

Normally you would read the file line by line, so the code is:

open my $in, "<:encoding(utf8)", $file or die "$file: $!";
while (my $line = <$in>) {
    chomp $line;
    # ...
}
close $in;

Read all the lines at once

Alternatively you might want to read the whole file into memory at once and hold it in an array where each line is a separate element:

open my $in, "<:encoding(utf8)", $file or die "$file: $!";
my @lines = <$in>;
close $in;

chomp @lines;
for my $line (@lines) {
    # ...
}

The latter has the disadvantage that it can only handle files that will fit into the memory of the computer, but sometime it is mor convenient to have all the file in memory at once.

split

Finally, if you really want to use the split function, you could read the whole file into memory using slurp and then split it along the newlines, though I don't know when would this have any advantage over the other methods.

my @lines = read_lines('some_file.txt');

sub read_lines {
    my ($file) = @_;

    open my $in, "<:encoding(utf8)", $file or die "$file: $!";
    local $/ = undef;
    my $content = <$in>;
    close $in;
    return split /\n/, $content;
}

Comments

i want to split a,b,c d,e,f g,h,i as a b c d e f g h i

please help how to do it. --- What is this. A string? A file? What is the input? What is the expected output? What have you tried so far?

---

a,b,c d,e,f g,h,i

are data in a file.

i want another file which gives output as

a b c d e f g h i

----

So what code did you write already?

---- system("sed -n '3,220p' IOSS_DUT_with_BISS_NoC.v > tmp.txt"); my $out = "output_rtl.txt"; open(OUT, ">> $out") or die $!; my $in ="tmp.txt"; open(IN, "<" ,$in) or die $!; @line = ; my $len = @line; for(my $i=0;$i<$len;$i++){ #@flow = #($var1,$var2,$line[$i]) = split(/\s+/,$line[$i]); #if($line[$i] =~ m/output/){ # $line[$i] =~ s/output.*'\s/\s.*/g;

@field = split(/,\s/, "$line[$i]"); #@field2 = split(/\s+/,"@field"); print OUT "\n@field"; }

assume format of data in files as mentioned above.

I am new to perl so please help with the sample data i provided earlier. i need that code which execute the dummy query i posted first.

---- In the Perl Tutorial https://perlmaven.com/perl-tutorial read "Open and read from files using Perl" and Writing to files

and also splitThese will probably help you. ----

Have you managed it? Here is a solution for you: https://perlmaven.com/flatten-csv-file

---

I want to split a student file into fields: Name, Country, course, Student, ID, local,English,en,3232 local,French,md,76454 International,English,ch,124151 local,English,en,124135 International,Chinese,lit,23747

how do I split this than loop through if an argument is given "./search.pl -l English file.txt" where -l is the option that does the procedure scans the file, checks to identify lang breaks them up and display

English local: 2 International: 1

if I put "./search.pl -l Chinese file.txt "

Chinese local: 0 International: 1

--- I would not call that splitting as you create a totally different forma. Try to rephrase your question, that will help you to think about it. Then show what have you written so far.

---

I want create a file of tab-seperated values ,including a line that has the names of each column of values example input: First Last Score Jack Flintstone 330 Barney Jerry 195

output: First : Jack Last : Flintstone Score : 330 First : Barney Last : Jerry Score : 195 --- Good for you, and what is the problem? When you say "input" is this another file? What did you write so far?

---