How do I efficiently parse a CSV file in Perl?

by

The right way to do it — by an order of magnitude — is to use Text::CSV_XS. It will be much faster and much more robust than anything you’re likely to do on your own. If you’re determined to use only core functionality, you have a couple of options depending on speed vs robustness.

About the fastest you’ll get for pure-Perl is to read the file line by line and then naively split the data:

my $file="somefile.csv";
my @data;
open(my $fh, '<', $file) or die "Can't read file '$file' [$!]\n";
while (my $line = <$fh>) {
    chomp $line;
    my @fields = split(/,/, $line);
    push @data, \@fields;
}

This will fail if any fields contain embedded commas. A more robust (but slower) approach would be to use Text::ParseWords. To do that, replace the split with this:

    my @fields = Text::ParseWords::parse_line(',', 0, $line);

More Related Contents:

  1. How can I read and parse CSV files in C++?
  2. How can I parse dates and convert time zones in Perl?
  3. How does Perl parse unquoted bare words?
  4. How do I convert a date/time to epoch time (unix time/seconds since 1970) in Perl?
  5. How can I extract text from a PDF file in Perl?
  6. I want to read a file from a directory folder [duplicate]
  7. How can I match values in one file to ranges from another?
  8. Perl: Compare 2 hash table values
  9. how to use multiple IP’s in perl script
  10. How can I use a new Perl module without install permissions?
  11. When should I use the & to call a Perl subroutine?
  12. What’s the difference between my ($variableName) and my $variableName in Perl?
  13. Parsing CSV using OleDb using C#
  14. How can I generate all permutations of an array in Perl?
  15. How can I install CPAN modules locally without root access (DynaLoader.pm line 229 error)?
  16. OpenSSL DH Key Too Small Error
  17. Manual installation of a Perl Module
  18. How to extract information between two unique words in a large text file
  19. @ARGV is empty using ActivePerl in Windows 7
  20. ImageMagick Command-Line Option Order (and Categories of Command-Line Parameters)
  21. Perl Dereferencing Syntax
  22. How to extrace pg_backend_pid from postgresql in shell script and pass it to another process?
  23. What exactly does Perl’s “bless” do?
  24. What is the difference between `$this`, `@that`, and `%those` in Perl?
  25. Use Scala parser combinator to parse CSV files
  26. Why are use warnings; use strict; not default in Perl?
  27. What is the difference between `read` and `sysread`?
  28. How to use shell variables in perl command call in a bash shell script?
  29. In Perl, what is the difference between accessing an array element using @a[$i] as opposed to using $a[$i]?
  30. How do I use symbolic references in Perl?

Leave a Comment