Text::CSV - comma-separated values manipulator (using XS or PurePerl)
use Text::CSV; $csv = Text::CSV->new(); # create a new object # If you want to handle non-ascii char. $csv = Text::CSV->new({binary => 1}); $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 $diag = $csv->error_diag (); # if an error occured, explains WHY $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 $eof = $csv->eof (); # Indicate if last parse or # getline () hit End Of File $csv->types(\@t_array); # Set column types
Text::CSV provides facilities for the composition and decomposition of comma-separated values using Text::CSV_XS or its pure Perl version.
An instance of the Text::CSV 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.
This module, Text::CSV was firstly written by Alan Citterman which could deal with only ascii characters. Then, Jochen Wiedmann wrote Text::CSV_XS which has the binary mode. This XS version is maintained by H.Merijn Brand and Text::CSV_PP written by Makamaka was pure-Perl version of Text::CSV_XS.
Now, Text::CSV was rewritten by Makamaka and become a wrapper to Text::CSV_XS or Text::CSV_PP. Text::CSV_PP will be bundled in this distribution.
When you use Text::CSV, it calls a backend worker module - Text::CSV_XS or Text::CSV_PP. By default, Text::CSV tries to use Text::CSV_XS which must be complied and installed properly. If this call is fail, Text::CSV uses Text::CSV_PP.
The required Text::CSV_XS version is 0.32 in Text::CSV version 1.00.
If you set an enviornment variable PERL_TEXT_CSV, The calling action will be changed.
PERL_TEXT_CSV
Always use Text::CSV_PP
(The default) Use compiled Text::CSV_XS if it is properly compiled & installed, otherwise use Text::CSV_PP
Always use compiled Text::CSV_XS, die if it isn't properly compiled & installed.
These ideas come from DBI::PurePerl mechanism.
example:
BEGIN { $ENV{PERL_TEXT_CSV} = 0 } use Text::CSV; # always uses Text::CSV_PP
In future, it may be able to specify another module.
The default behavior is to only accept ascii characters. In many cases, you should create a Text::CSV object with binary mode.
my $csv = Text::CSV->new({binary => 1});
See to "Embedded newlines" in Text::CSV_XS.
See to "SPECIFICATION" in Text::CSV_XS.
These methods are common between XS and puer Perl version. Most of the document was shamelessly copied and replaced from Text::CSV_XS.
(Class method) Returns the current module version. Not worker module version. If you want the worker module version, you can use module method.
module
print Text::CSV->version; # This module version print Text::CSV->module->version; # The version of the worker module
(Class method) Returns a new instance of Text::CSV. The objects attributes are described by the (optional) hash ref \%attr. Currently the following attributes are available:
\%attr
An end-of-line string to add to rows, usually undef (nothing, default), "\012" (Line Feed) or "\015\012" (Carriage Return, Line Feed).
undef
"\012"
"\015\012"
See to Text::CSV_XS.
The char used for separating fields, by default a comma. (,). Limited to a single-byte character, usually in the range from 0x20 (space) to 0x7e (tilde).
,
The separation character can not be equal to the quote character. The separation character can not be equal to the escape character.
When this option is set to true, whitespace (TAB's and SPACE's) surrounding the separation character is removed when parsing. So lines like:
1 , "foo" , bar , 3 , zapp
are now correctly parsed, even though it violates the CSV specs.
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). Limited to a single-byte character, usually in the range from 0x20 (space) to 0x7e (tilde).
"
The quote character can not be equal to the separation character.
By default, parsing fields that have quote_char characters inside an unquoted field, like
quote_char
1,foo "bar" baz,42
would result in a parse error. Though it is still bad practice to allow this format, we cannot help there are some vendors that make their applications spit out lines styled like this.
The character used for escaping certain characters inside quoted fields. Limited to a single-byte character, usually in the range from 0x20 (space) to 0x7e (tilde).
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:
escape_char
"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.
By default, parsing fields that have escape_char characters that escape characters that do not need to be escaped, like:
my $csv = Text::CSV->new ({ escape_char => "\\" }); $csv->parse (qq{1,"my bar\'s",baz,42});
would result in a parse error. Though it is still bad practice to allow this format, this option enables you to treat all escape character sequences equal.
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.
"0
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.
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.
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.
meta_info ()
is_quoted ()
is_binary ()
To sum it up,
$csv = Text::CSV->new ();
is equivalent to
$csv = Text::CSV->new ({ quote_char => '"', escape_char => '"', sep_char => ',', eol => '', always_quote => 0, binary => 0, keep_meta_info => 0, allow_loose_quotes => 0, allow_loose_escapes => 0, allow_whitespace => 0, verbatim => 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.
$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.
string ()
error_input ()
$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.
\*FILE
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.
$line = $csv->string ();
This object function returns the input to parse () or the resultant CSV string of combine (), whichever was called more recently.
parse ()
combine ()
$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.
fields ()
You may use the types () method for setting column types. See the description below.
$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.
$eof = $csv->eof ();
If parse () or getline () was used with an IO stream, this method will return true (1) if the last call hit end of file, otherwise it will return false (''). This is useful to see the difference between a failure and end of file.
getline ()
$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::IV (), Text::CSV::NV (), Text::CSV::NV (), Text::CSV::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 ();
Set field type to integer.
Set field type to numeric/float.
Set field type to string.
@columns = $csv->fields ();
This object function returns the input to combine () or the resultant decomposed fields of parse (), whichever was called more recently.
@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:
The field was quoted.
The field was binary.
See the is_*** () methods below.
is_*** ()
my $quoted = $csv->is_quoted ($column_idx);
Where $column_idx is the (zero-based) index of the column in the last result of parse ().
$column_idx
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.
,20070108,
,"20070108",
my $binary = $csv->is_binary ($column_idx);
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 = $csv->status ();
This object function returns success (or failure) of combine () or parse (), whichever was called more recently.
$bad_argument = $csv->error_input ();
This object function returns the erroneous argument (if it exists) of combine () or parse (), whichever was called more recently.
$csv->error_diag (); $error_code = 0 + $csv->error_diag (); $error_str = "" . $csv->error_diag (); ($cde, $str) = $csv->error_diag ();
If (and only if) an error occured, this function returns the diagnostics of that error.
If called in void context, it will print the internal error code and the associated error message to STDERR.
If called in list context, it will return the error code and the error message in that order.
If called in scalar context, it will return the diagnostics in a single scalar, a-la $!. It will contain the error code in numeric context, and the diagnostics message in string context.
Depending on the used worker module, returned diagnostics is diffferent.
Text::CSV_XS parses csv strings by dividing one character while Text::CSV_PP by using the regular expressions. That difference makes the different cause of the failure.
Some methods are Text::CSV only.
(Class method) Returns the module name called by Text::CSV.
(Object method) Returns the used module name in creating it.
At current, the worker module is decided once when Text::CSV is used in a program.
Returns true value if Text::CSV or the object uses XS module as worker.
Returns true value if Text::CSV or the object uses pure-Perl module as worker.
If an error occured, $csv->error_diag () can be used to get more information on the cause of the failure. Note that for speed reasons, the internal value is never cleared on success, so using the value returned by error_diag () in normal cases - when no error occured - may cause unexpected results.
This function changes depending on the used module (XS or PurePerl).
See to "DIAGNOSTICS" in Text::CSV_XS and "DIAGNOSTICS" in Text::CSV_PP.
Currently the wrapper mechanism is to change symbolic table for speed.
for my $method (@PublicMethods) { *{"Text::CSV::$method"} = \&{"$class\::$method"}; }
But how about it - calling worker module object?
sub parse { my $self = shift; $self->{_WORKER_OBJECT}->parse(@_); # XS or PP CSV object }
$csv = Text::CSV->simple;
$csv = Text::CSV->new ({ quote_char => '"', escape_char => '"', sep_char => ',', eol => '', binary => 1, allow_loose_quotes => 1, allow_loose_escapes => 1, allow_whitespace => 1, });
Is it needless?
See to "TODO" in Text::CSV_XS and "TODO" in Text::CSV_PP.
Text::CSV_PP(3) and Text::CSV_XS(3).
Alan Citterman <alan[at]mfgrtl.com> wrote the original Perl module. Please don't send mail concerning Text::CSV to Alan, as he's not a present maintainer.
Jochen Wiedmann <joe[at]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[at]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.
Makamaka Hannyaharamitu, <makamaka[at]cpan.org> wrote Text::CSV_PP which is the pure-Perl version of Text::CSV_XS.
New Text::CSV (since 0.99) is maintained by Makamaka.
Text::CSV
Copyright (C) 1997 Alan Citterman. All rights reserved. Copyright (C) 2007 Makamaka Hannyaharamitu.
Text::CSV_PP:
Copyright (C) 2005-2007 Makamaka Hannyaharamitu.
Text:CSV_XS:
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.
To install Text::CSV, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Text::CSV
CPAN shell
perl -MCPAN -e shell install Text::CSV
For more information on module installation, please visit the detailed CPAN module installation guide.