Path::Tiny handles opening and closing and doing different things to a file. Its methods include spew(), but the module's own documentation recommends using append() for what you want since it locks the file and overwrites it, whereas spew() creates a temporary copy.

[18:25][nick:~/monks]$ cat 1135741.pl 
#! perl -w
use strict;
use feature qw/ say /;

use Path::Tiny qw/ path /;

my $file = 'test.dat';
my @lines = path( $file )->lines( { chomp => 1 } );

# do something with @lines ...

my @append = (); # empty array
path( $file )->append( @append, { truncate => 1 } );

say "Done.";

__END__
[download]

[18:25][nick:~/monks]$ cat test.dat
foo
bar
baz
quux
[download]

[18:26][nick:~/monks]$ perl 1135741.pl 
Done.
[download]

[18:26][nick:~/monks]$ cat test.dat
[18:26][nick:~/monks]$
[download]

Yeah, if preserving the existing file permissions is a goal, spew might change them

There is no need to give append an empty array, its the same as if you didn't give it an array  path( $file )->append({ truncate => 1 });

spew looks much nicer than a truncate option

Another way to is  truncate path( $file )->opena, 0; but that isn't much better than the previous one

Simply clobbering the file works but might not be as clear in intent as spew  path( $file )->openw;

A test

 $ perl -MPath::Tiny -le " my $f = path( 2 ); $f->spew(2); print $f->s
+lurp;  $f->openw; print $f->slurp; "
2
[download]

There is no need to give append an empty array

Not true according to testing:

[18:45][nick:~/monks]$ cat test.dat 
foo
bar
baz
quux

[18:45][nick:~/monks]$ cat 1135741.pl 
#! perl -w
use strict;
use feature qw/ say /;

use Path::Tiny qw/ path /;

my $file = 'test.dat';
my @lines = path( $file )->lines( { chomp => 1 } );

#my @append = (); # empty array
path( $file )->append( '', { truncate => 1 } );

say "Done.";

__END__

[18:45][nick:~/monks]$ perl !$
perl 1135741.pl
Done.
[18:45][nick:~/monks]$ cat test.dat 
foo
bar
baz
quux

HASH(0x7fa310898690)
[download]

The way forward always starts with a minimal test.

Hi, Can you explain me this in more detail. I am not aware of the functions you are using. Thanks Rohit

I don't understand what you're asking me. You asked how to "clear the contents of the text file" and the code I posted does that .