Perl Script Hangs on Empty File

I have the attached perl script which formats a file. However if the file is empty, the perl script hangs. Can you please edit the script so it exits if the file is empty?
PostProcess.txt
copiacapAsked:
Who is Participating?
 
Justin MathewsConnect With a Mentor Commented:
My previous solution will exit if it finds a blank line. To exit with error if the input file is empty use the following:

my $input = $ARGV[0] || die "Please specify input file\n";
-s $input || die "Empty input file\n";
open(INPUT, $input) || die "Can't open input file $input: $!\n";
1 while( ($_=<INPUT>) !~ /^name\s+number\s+symbol\s+initial/);
do{
   chomp;
   my @F = split/\t/;
   print join("\t",@F[0..14])."\n";
} while( <INPUT> );
close(INPUT);
0
 
Justin MathewsCommented:
my $input = $ARGV[0] || die "Please specify input file\n";
open(INPUT, $input) || die "Can't open input file $input: $!\n";
1 while( ($_=<INPUT>) !~ /^name\s+number\s+symbol\s+initial/ && /./);
do {
   chomp;
   my @F = split/\t/;
   print join("\t",@F[0..14])."\n";
} while( <INPUT> );
close(INPUT);
0
 
ozoCommented:
my $input = $ARGV[0] || die "Please specify input file\n";
open(INPUT, $input) || die "Can't open input file $input: $!\n";
while( <INPUT> ){
  next unless /^name\s+number\s+symbol\s+initial/..0;
   chomp;
   my @F = split/\t/;
   print join("\t",@F[0..14])."\n";
}
0
 
ozoCommented:
that still hangs on a non-empty file that does not contain name\s+number\s+symbol\s+initial
0
 
Justin MathewsCommented:
Sorry, try this:

my $input = $ARGV[0] || die "Please specify input file\n";
-s $input || die "Empty input file\n";
open(INPUT, $input) || die "Can't open input file $input: $!\n";

while ($_=<INPUT>) {/^name\s+number\s+symbol\s+initial/ && last}

do{
   chomp;
   my @F = split/\t/;
   print join("\t",@F[0..14])."\n";
} while( <INPUT> );
close(INPUT);
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.