Perl: insert elements of array in file by substitution

Question

1) I have a textfile. The file contains a STRING that needs to be substituted with multiple lines, those lines are elements of an array.

Contents of file:

line 1  
line 2   
line 3  
STRING  
line 4  
...  

2.)I have an array

@array = qw (ele1 ele2 ele3);

This array can have 2 or more elements.

3.)I want to open the file, substitute the STRING with following pseudocode:

s/STRING/@array/;  

and write results in a new file.

4.) The new file with result should look like this :

line 1  
line 2   
line 3  
ele1  
ele2  
ele3
line 4  
...

Here a piece of pseudocode:

open (FILE "< file.txt");
open (OUTPUT "> new.txt");
@array=qw(ele1 ele2 ele3);
for $line (<FILE>) {
    s/STRING/@array/;
    print OUTPUT "$line\n";
}
close FILE;
close OUTPUT;

Any suggestions on how to insert elements of an array into this file using substitution?

I am not looking for solutions based on sed, awk, cat or Unix shell tools.

Answer 1

You could do:

my $str = "line 1
line 2
line 3
STRING
line 4";
my @array = qw (ele1 ele2 ele3);
$str =~ s/STRING/join"\n",@array/e;
say $str;

Output:

line 1
line 2
line 3
ele1
ele2
ele3
line 4