The function you seek is... seek

use strict;
use warnings;

open my $fh, ">", "testing1.txt";
print $fh "stat";
seek $fh, 0, 0;
print $fh "stat-updated";
close $fh;

system cat => "testing1.txt";
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Yes, seek works in this case because the final output is longer than the initial output. But a word of caution is in order. Consider:

#! perl
use strict;
use warnings;

my $filename = 'test.txt';
open(my $fh, '>', $filename) or die "Cannot open file '$filename' for 
+writing: $!";
print $fh "The quick brown fox jumped over the unfortunate dog.";
seek $fh, 0, 0;
print $fh "The final output.";
close($fh) or die "Cannot close file '$filename': $!";
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This results in file “test.txt” containing:

The final output.ox jumped over the unfortunate dog.
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as seeking to the beginning of the file does not erase its existing contents.

Athanasius <°(((>< contra mundum

Iustus alius egestas vitae, eros Piratica,

So I will have to open and close the file agin in order to completely truncate watever is written in previous write attempts?

Yeah, gotta watch out for those output-oxen. ;-)

Yes, closing the filehandle and re-opening for writing with ">" will truncate the file. See open and perlopentut.

Note that you should test open’s return value. Either

use autodie;
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or write

open(my $file1, ">", "testing1.txt") or die "Cannot open file 'testing
+1.txt' for writing: $!";
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Also note that a lexical variable (as shown) is preferable to a bareword for the filehandle.

Hope that helps,