Writing to an output file

ameezys has asked for the wisdom of the Perl Monks concerning the following question:

my $filename = 'c:\Users\a\Desktop\b\c\test_3.v';

open(FH, '<', $filename) or die "Format of bench file name: circuit_na
+me.v \n example : s1423.v\n";

while(<FH>)
{
print "Hello";
}

print "Hello too";

close(FH);
[download]

I am currently reading an input file. However I want to print out everything inside and outside the while loop into a new output text file. Ex: output.txt. How do I get all the printing to write into a new file? Ive been reading and did some search on the internet but still couldn't figure it out.

Comment on Writing to an output file Download Code

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Re: Writing to an output file by haukex (Archbishop) on Apr 17, 2019 at 21:15 UTC
I would recommend you read through perlintro, it's not very long and it shows how to do basic file I/O, for example: `my $filename = "output.txt"; open my $fh, '>', $filename or die "$filename: $!"; print $fh "Hello"; close $fh;` [download]	[reply] [d/l]
Re: Writing to an output file by 1nickt (Canon) on Apr 17, 2019 at 21:18 UTC
Hi, `open(FH, '<', $filename) or die ...` Better written as `open(my $IN_FH, '<', $filename) or die ...; while (<$IN_FH>) { ... }` [download] So, if "`<`" is the second arg for when you want to read from a file ... See (please, for goodness' sake, see) https://perldoc.perl.org/perlintro.html#Files-and-I%2fO The way forward always starts with a minimal test.	[reply] [d/l] [select]
Re: Writing to an output file by AnomalousMonk (Archbishop) on Apr 17, 2019 at 21:51 UTC
Ive been reading and did some search on the internet ... I find that hard to believe. ... but still couldn't figure it out. That I can believe. In addition to the links given by others, please see the articles in the Monastery's Tutorials -> Input and Output section, open, and perlopentut. (Update: And see also the autodie pragma.) Give a man a fish: `<%-{-{-{-<`	[reply] [d/l]
Re: Writing to an output file by hippo (Bishop) on Apr 18, 2019 at 08:50 UTC
How do I get all the printing to write into a new file? See select.	[reply]
Re^2: Writing to an output file by haukex (Archbishop) on Apr 18, 2019 at 18:44 UTC
See select. A very good point regarding the "all the printing" part of the question! ameezys: Note that the effect of select is global, so it has the potential of affecting code in modules that you call after the `select`, and if you want to resume printing to `STDOUT` after writing the file, you'll have to store the return value of the first `select` to use for restoring the output handle later. Note you can always print to a specific filehandle, e.g. `print {$filehandle} $output;` or `print STDOUT $output;`.	[reply] [d/l] [select]


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