Writing all relevant data in one file to a new file with adjustments

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

Hi there, My problems lies with being unable to figure out how to replace a particular word/line with another word/line, and then write the data which was read in from the first file to another file with the replacement word rather than the orignal word. Here is what i have done so far in a shortcut

open my $file, $firstTextFile or die "Unable to open"!
while(<$file>){
if($_ =~ /hue/){
 $_ =~ s/hue/someword/g;
// How do i now write to a text file all the previous things in the fi
+rst text file except for the word hue being replaced with the word so
+meword in the new text file? 
}
}
[download]

Comment on Writing all relevant data in one file to a new file with adjustments Download Code

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Re: Writing all relevant data in one file to a new file with adjustments by pme (Monsignor) on Feb 08, 2015 at 20:43 UTC
Just open another filehandler and print the lines into it. `my $infilename = 'infile.txt'; my $outfilename = 'outfile.txt'; open my $infile, "<$infilename" or die "Unable to open $infilename $!" +; open my $outfile, ">$outfilename" or die "Unable to open $outfilename +$!"; while (<$infile>) { s/hue/someword/g; print $outfile $_; } close $infile; close $outfile;` [download]	[reply] [d/l]
Re: Writing all relevant data in one file to a new file with adjustments by Laurent_R (Canon) on Feb 08, 2015 at 22:09 UTC
pme has given the solution and also corrected implicitly what I am just going to say, but I want to comment it explicitly. When you write: `if($_ =~ /hue/){ $_ =~ s/hue/someword/g; }` [download] you don't really need that `if` conditional: the substitution operator `$_ =~ s/hue/someword/g;` will anyway do the substitution only if the input line matches `/hue/`, so that the three code lines above can be summarized to `$_ =~ s/hue/someword/g;` [download] It can actually be simplified further by noting that that the substitution operator works by default on `$_`, so that it can be rewritten: `s/hue/someword/g;` [download] but not everyone agrees with that further simplification, some people prefer to explicitly use the `$_` variable and the `=~` binding operator. The same simplification could have been done in the `if` conditional (`if (/hue/) { # ...`), but there is no point of discussing that further since it has already been removed. Je suis Charlie.	[reply] [d/l] [select]