NAME

Text::CSV_XS - comma-separated values manipulation routines

SYNOPSIS

use Text::CSV_XS;

$csv = Text::CSV_XS->new ();          # create a new object
$csv = Text::CSV_XS->new (\%attr);    # create a new object

$status  = $csv->combine (@columns);  # combine columns into a string
$line    = $csv->string ();           # get the combined string

$status  = $csv->parse ($line);       # parse a CSV string into fields
@columns = $csv->fields ();           # get the parsed fields

$status       = $csv->status ();      # get the most recent status
$bad_argument = $csv->error_input (); # get the most recent bad argument

$status = $csv->print ($io, $colref); # Write an array of fields
                                      # immediately to a file $io
$colref = $csv->getline ($io);        # Read a line from file $io,
                                      # parse it and return an array
                                      # ref of fields

$csv->types (\@t_array);              # Set column types

DESCRIPTION

Text::CSV_XS provides facilities for the composition and decomposition of comma-separated values. An instance of the Text::CSV_XS class can combine fields into a CSV string and parse a CSV string into fields.

The module accepts either strings or files as input and can utilize any user-specified characters as delimiters, separators, and escapes so it is perhaps better called ASV (anything separated values) rather than just CSV.

Embedded newlines

Important Note: The default behaviour is to only accept ascii characters. This means that fields can not contain newlines. If your data contains newlines embedded in fields, or characters above 0x7e (tilde), or binary data, you *must* set binary = 1> in the call to new (). To cover the widest range of parsing options, you will always want to set binary.

But you still have the problem that you have to pass a correct line to the parse () method, which is more complicated from the usual point of usage:

my $csv = Text::CSV_XS->new ({ binary => 1, eol => $/ });
while (<>) {
    $csv->parse ($_);
    my @fields = $csv->fields ();

will break, as the while might read broken lines, as that doesn't care about the quoting. If you need to support embedd newlines, the way to go is either

use IO::Handle;
my $csv = Text::CSV_XS->new ({ binary => 1, eol => $/ });
while (my $row = $csv->getline (*ARGV)) {
    my @fields = @$row;

or, more safely in perl 5.6 and up

my $csv = Text::CSV_XS->new ({ binary => 1, eol => $/ });
open my $io, "<", $file or die "$file: $!";
while (my $row = $csv->getline ($io)) {
    my @fields = @$row;

FUNCTIONS

version ()

(Class method) Returns the current module version.

new (\%attr)

(Class method) Returns a new instance of Text::CSV_XS. The objects attributes are described by the (optional) hash ref \%attr. Currently the following attributes are available:

quote_char

The char used for quoting fields containing blanks, by default the double quote character ("). A value of undef suppresses quote chars. (For simple cases only).

The quote character can not be equal to the separation character.

eol

An end-of-line string to add to rows, usually undef (nothing, default), "\012" (Line Feed) or "\015\012" (Carriage Return, Line Feed)

If both $/ and eol equal "\015", parsing lines that end on only a Carriage Return without Line Feed, will be parsed correct. Line endings, wheather in $/ or eol, other than undef, "\n", "\r\n", or "\r" are not (yet) supported for parsing.

escape_char

The character used for escaping certain characters inside quoted fields.

The escape_char defaults to being the literal double-quote mark (") in other words, the same as the default quote_char. This means that doubling the quote mark in a field escapes it:

"foo","bar","Escape ""quote mark"" with two ""quote marks""","baz"

If you change the default quote_char without changing the default escape_char, the escape_char will still be the quote mark. If instead you want to escape the quote_char by doubling it, you will need to change the escape_char to be the same as what you changed the quote_char to.

The escape character can not be equal to the separation character.

sep_char

The char used for separating fields, by default a comma. (,)

The separation character can not be equal to the quote character. The separation character can not be equal to the escape character.

binary

If this attribute is TRUE, you may use binary characters in quoted fields, including line feeds, carriage returns and NULL bytes. (The latter must be escaped as "0.) By default this feature is off.

types

A set of column types; this attribute is immediately passed to the types method below. You must not set this attribute otherwise, except for using the types method. For details see the description of the types method below.

always_quote

By default the generated fields are quoted only, if they need to, for example, if they contain the separator. If you set this attribute to a TRUE value, then all fields will be quoted. This is typically easier to handle in external applications. (Poor creatures who aren't using Text::CSV_XS. :-)

keep_meta_info

By default, the parsing of input lines is as simple and fast as possible. However, some parsing information - like quotation of the original field - is lost in that process. Set this flag to true to be able to retrieve that information after parsing with the methods meta_info (), is_quoted (), and is_binary () described below. Default is false.

To sum it up,

$csv = Text::CSV_XS->new ();

is equivalent to

$csv = Text::CSV_XS->new ({
    quote_char     => '"',
    escape_char    => '"',
    sep_char       => ',',
    eol            => '',
    always_quote   => 0,
    binary         => 0,
    keep_meta_info => 0,
    });

For all of the above mentioned flags, there is an accessor method available where you can inquire for the current value, or change the value

my $quote = $csv->quote_char;
$csv->binary (1);

It is unwise to change these settings halfway through writing CSV data to a stream. If however, you want to create a new stream using the available CSV object, there is no harm in changing them.

combine

$status = $csv->combine (@columns);

This object function constructs a CSV string from the arguments, returning success or failure. Failure can result from lack of arguments or an argument containing an invalid character. Upon success, string () can be called to retrieve the resultant CSV string. Upon failure, the value returned by string () is undefined and error_input () can be called to retrieve an invalid argument.

print

$status = $csv->print ($io, $colref);

Similar to combine, but it expects an array ref as input (not an array!) and the resulting string is not really created, but immediately written to the $io object, typically an IO handle or any other object that offers a print method. Note, this implies that the following is wrong:

open FILE, ">", "whatever";
$status = $csv->print (\*FILE, $colref);

The glob \*FILE is not an object, thus it doesn't have a print method. The solution is to use an IO::File object or to hide the glob behind an IO::Wrap object. See IO::File(3) and IO::Wrap(3) for details.

For performance reasons the print method doesn't create a result string. In particular the $csv->string (), $csv->status (), $csv-fields ()> and $csv->error_input () methods are meaningless after executing this method.

string

$line = $csv->string ();

This object function returns the input to parse () or the resultant CSV string of combine (), whichever was called more recently.

parse

$status = $csv->parse ($line);

This object function decomposes a CSV string into fields, returning success or failure. Failure can result from a lack of argument or the given CSV string is improperly formatted. Upon success, fields () can be called to retrieve the decomposed fields . Upon failure, the value returned by fields () is undefined and error_input () can be called to retrieve the invalid argument.

You may use the types () method for setting column types. See the description below.

getline

$colref = $csv->getline ($io);

This is the counterpart to print, like parse is the counterpart to combine: It reads a row from the IO object $io using $io->getline () and parses this row into an array ref. This array ref is returned by the function or undef for failure.

The $csv->string (), $csv->fields () and $csv->status () methods are meaningless, again.

types

$csv->types (\@tref);

This method is used to force that columns are of a given type. For example, if you have an integer column, two double columns and a string column, then you might do a

$csv->types ([Text::CSV_XS::IV (),
              Text::CSV_XS::NV (),
              Text::CSV_XS::NV (),
              Text::CSV_XS::PV ()]);

Column types are used only for decoding columns, in other words by the parse () and getline () methods.

You can unset column types by doing a

$csv->types (undef);

or fetch the current type settings with

$types = $csv->types ();

IV: Set field type to integer.
NV: Set field type to numeric/float.
PV: Set field type to string.

fields

@columns = $csv->fields ();

This object function returns the input to combine () or the resultant decomposed fields of parse (), whichever was called more recently.

meta_info

@flags = $csv->meta_info ();

This object function returns the flags of the input to combine () or the flags of the resultant decomposed fields of parse (), whichever was called more recently.

For each field, a meta_info field will hold flags that tell something about the field returned by the fields () method or passed to the combine () method. The flags are bitwise-or'd like:

0x0001: The field was quoted.
0x0002: The field was binary.

See the is_*** () methods below.

is_quoted

my $quoted = $csv->is_quoted ($column_idx);

Where $column_idx is the (zero-based) index of the column in the last result of parse ().

This returns a true value if the data in the indicated column was enclosed in quote_char quotes. This might be important for data where ,20070108, is to be treated as a numeric value, and where ,"20070108", is explicitly marked as character string data.

is_binary

my $binary = $csv->is_binary ($column_idx);

Where $column_idx is the (zero-based) index of the column in the last result of parse ().

This returns a true value if the data in the indicated column contained any byte in the range [\x00-\x08,\x10-\x1F,\x7F-\xFF]

status

$status = $csv->status ();

This object function returns success (or failure) of combine () or parse (), whichever was called more recently.

error_input

$bad_argument = $csv->error_input ();

This object function returns the erroneous argument (if it exists) of combine () or parse (), whichever was called more recently.

INTERNALS

Combine (...)
Parse (...)

The arguments to these two internal functions are deliberately not described or documented to enable the module author(s) to change it when they feel the need for it and using them is highly discouraged as the API may change in future releases.

EXAMPLES

An example for creating CSV files:

use Text::CSV_XS;

my $csv = Text::CSV_XS->new;

open my $csv_fh, ">", "hello.csv" or die "hello.csv: $!";

my @sample_input_fields = (
    'You said, "Hello!"',   5.67,
    '"Surely"',   '',   '3.14159');
if ($csv->combine (@sample_input_fields)) {
    my $string = $csv->string;
    print $csv_fh "$string\n";
    }
else {
    my $err = $csv->error_input;
    print "combine () failed on argument: ", $err, "\n";
    }
close $csv_fh;

An example for parsing CSV lines:

use Text::CSV_XS;

my $csv = Text::CSV_XS->new ({ keep_meta_info => 1, binary => 1 });

my $sample_input_string =
    qq{"I said, ""Hi!""",Yes,"",2.34,,"1.09","\x{20ac}",};
if ($csv->parse ($sample_input_string)) {
    my @field = $csv->fields;
    foreach my $col (0 .. $#field) {
        my $quo = $csv->is_quoted ($col) ? $csv->{quote_char} : "";
        printf "%2d: %s%s%s\n", $col, $quo, $field[$col], $quo;
        }
    }
else {
    my $err = $csv->error_input;
    print "parse () failed on argument: ", $err, "\n";
    }

CAVEATS

This module is based upon a working definition of CSV format which may not be the most general.

Allowable characters within a CSV field include 0x09 (tab) and the inclusive range of 0x20 (space) through 0x7E (tilde). In binary mode all characters are accepted, at least in quoted fields:
A field within CSV may be surrounded by double-quotes. (The quote char)
A field within CSV must be surrounded by double-quotes to contain a comma. (The separator char)
A field within CSV must be surrounded by double-quotes to contain an embedded double-quote, represented by a pair of consecutive double-quotes. In binary mode you may additionally use the sequence "0 for representation of a NULL byte.
A CSV string may be terminated by 0x0A (line feed) or by 0x0D,0x0A (carriage return, line feed).

TODO

eol

Discuss an option to make the eol honor the $/ setting. Maybe

my $csv = Text::CSV_XS->new ({ eol => $/ });

is already enough, and new options only make things less opaque.

setting meta info

Future extensions might include extending the fields_flags (), is_quoted (), and is_binary () to accept setting these flags for fields, so you can specify which fields are quoted in the combine ()/string () combination.

$csv->meta_info (0, 1, 1, 3, 0, 0);
$csv->is_quoted (3, 1);

parse returning undefined fields

Adding an option that enables the parser to distinguish between empty fields and undefined fields, like

$csv->quote_always (1);
$csv->allow_undef (1);
$csv->parse (qq{,"",1,"2",,""});
my @fld = $csv->fields ();

Then would return (undef, "", "1", "2", undef, "") in @fld, instead of the current ("", "", "1", "2", "", "").

combined methods

Adding means (methods) that combine combine () and string () in a single call. Likewise for parse () and fields (). Given the trouble with embedded newlines, maybe just allowing getline () and print () is sufficient.

Unicode

Make parse () and combine () do the right thing for Unicode (UTF-8) if requested. See t/50_utf8.t. More complicated, but evenly important, also for getline () and print ().

Space delimited seperators

Discuss if and how Text::CSV_XS should/could support formats like

1 , "foo" , "bar" , 3.19 ,

Double double quotes

There seem to be applications around that write their dates like

1,4,""12/11/2004"",4,1

If we would support that, in what way?

Parse the whole file at once

Implement a new methods that enables the parsing of a complete file at once, returning a lis of hashes. Possible extension to this could be to enable a column selection on the call:

my @AoH = $csv->parse_file ($filename, { cols => [ 1, 4..8, 12 ]});

Returning something like

[ { fields => [ 1, 2, "foo", 4.5, undef, "", 8 ],
    flags  => [ ... ],
    errors => [ ... ],
    },
  { fields => [ ... ],
    .
    .
    },
  ]

AUTHORS and MAINTAINERS

Alan Citterman <alan@mfgrtl.com> wrote the original Perl module. Please don't send mail concerning Text::CSV_XS to Alan, as he's not involved in the C part which is now the main part of the module.

Jochen Wiedmann <joe@ispsoft.de> rewrote the encoding and decoding in C by implementing a simple finite-state machine and added the variable quote, escape and separator characters, the binary mode and the print and getline methods. See ChangeLog releases 0.10 through 0.23.

H.Merijn Brand <h.m.brand@xs4all.nl> cleaned up the code, added the field flags methods, wrote the major part of the test suite, completed the documentation, fixed some RT bugs. See ChangeLog releases 0.25 and on.

COPYRIGHT AND LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

To install Text::CSV_XS, copy and paste the appropriate command in to your terminal.

cpanm

cpanm Text::CSV_XS

CPAN shell

perl -MCPAN -e shell
install Text::CSV_XS

For more information on module installation, please visit the detailed CPAN module installation guide.

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