Re^2: How to have perl check line length

So I added it like below to my script, but it doesn't work. Am I missing something else?

open(NPBXNUM1, ">npbxnum1");
open(MYINPUTFILE, "npbxnum");

while (<MYINPUTFILE>) {
chomp;
$line .= '_' x (4 - length $line);
}

close(MYINPUTFILE);
close(NPBXNUM1);

system "mv npbxnum1 npbxnum";
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Re^3: How to have perl check line length by SuicideJunkie (Vicar) on Sep 17, 2013 at 18:14 UTC
Replace $line with whatever variable you are storing the line in. (In this case, `$_`) Also, you should probably print the modified lines to the output file at some point inside the loop. PS: `use warnings; use strict;`, and opens in the form of `open my $filehandle, '<', $filename or die "I couldn't open the file. OS says: $!";` will help highlight likely mistakes in your code and illuminate the reasons for any file errors.	[reply] [d/l] [select]
Re^3: How to have perl check line length by marinersk (Priest) on Sep 17, 2013 at 18:44 UTC
You really, really, really should `use strict`, especially if you are new to Perl. It will save you from asking embarrassing questions. That is to say, being new to Perl, you might still have to ask: "What does `Global symbol "$line" requires explicit package name` mean?" But that's a much better question than "why didn't that line of code I stuck in my program work?" #!/usr/bin/perl -w use strict; { open(NPBXNUM1, ">npbxnum1"); open(MYINPUTFILE, "npbxnum"); while (<MYINPUTFILE>) { chomp; $line .= '_' x (4 - length $line); } close(MYINPUTFILE); close(NPBXNUM1); system "mv npbxnum1 npbxnum"; } exit; __END__ C:\Steve\Dev\PerlMonks\P-2013-09-17@2038-Use-Strict>usestrict.pl Global symbol "$line" requires explicit package name at C:\Steve\Dev\P +erlMonks\P-2013-09-17@2038-Use-Strict\usestrict.pl line 11. Global symbol "$line" requires explicit package name at C:\Steve\Dev\P +erlMonks\P-2013-09-17@2038-Use-Strict\usestrict.pl line 11. Execution of C:\Steve\Dev\PerlMonks\P-2013-09-17@2038-Use-Strict\usest +rict.pl aborted due to compilation errors. [download]	[reply] [d/l]