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.
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) - escape_char
-
The char used for escaping certain characters inside quoted fields, by default the same character. (
"
)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 ()
, andis_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 bystring ()
is undefined anderror_input ()
can be called to retrieve an invalid argument. -
$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 ofcombine ()
, 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 byfields ()
is undefined anderror_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 ofparse ()
, 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 ofparse ()
, 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 thecombine ()
method. The flags are bitwise-or'd like: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 ofparse ()
.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 ofparse ()
.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 ()
orparse ()
, whichever was called more recently. - error_input
-
$bad_argument = $csv->error_input ();
This object function returns the erroneous argument (if it exists) of
combine ()
orparse ()
, whichever was called more recently.
INTERNALS
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
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.
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);
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", "", "").
SEE ALSO
perl(1), IO::File(3), IO::Wrap(3), Spreadsheet::Read(3)
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.
H.Merijn Brand <h.m.brand@xs4all.nl> cleaned up the code and added the field flags methods.
COPYRIGHT AND LICENSE
Copyright (C) 2007-2007 H.Merijn Brand for PROCURA B.V. Copyright (C) 1998-2001 Jochen Wiedmann. All rights reserved. Portions Copyright (C) 1997 Alan Citterman. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.