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CentOS 7.0 - man page for text::csv_xs (centos section 3)

CSV_XS(3)		       User Contributed Perl Documentation			CSV_XS(3)

       Text::CSV_XS - comma-separated values manipulation routines

	use Text::CSV_XS;

	my @rows;
	my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });
	open my $fh, "<:encoding(utf8)", "test.csv" or die "test.csv: $!";
	while (my $row = $csv->getline ($fh)) {
	    $row->[2] =~ m/pattern/ or next; # 3rd field should match
	    push @rows, $row;
	close $fh;

	$csv->eol ("\r\n");
	open $fh, ">:encoding(utf8)", "new.csv" or die "new.csv: $!";
	$csv->print ($fh, $_) for @rows;
	close $fh or die "new.csv: $!";

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

       The module accepts either strings or files as input and support the use of user-specified
       characters for delimiters, separators, and escapes.

   Embedded newlines
       Important Note: The default behavior is to accept only ASCII characters in the range from
       0x20 (space) to 0x7E (tilde).  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 (<>) {	       #  WRONG!
	    $csv->parse ($_);
	    my @fields = $csv->fields ();

       will break, as the while might read broken lines, as that does not care about the quoting.
       If you need to support embedded newlines, the way to go is to not pass "eol" in the parser
       (it accepts "\n", "\r", and "\r\n" by default) and then

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

       The old(er) way of using global file handles is still supported

	while (my $row = $csv->getline (*ARGV)) {

       Unicode is only tested to work with perl-5.8.2 and up.

       On parsing (both for "getline" and "parse"), if the source is marked being UTF8, then all
       fields that are marked binary will also be marked UTF8.

       For complete control over encoding, please use Text::CSV::Encoded:

	use Text::CSV::Encoded;
	my $csv = Text::CSV::Encoded->new ({
	    encoding_in  => "iso-8859-1", # the encoding comes into   Perl
	    encoding_out => "cp1252",	  # the encoding comes out of Perl

	$csv = Text::CSV::Encoded->new ({ encoding  => "utf8" });
	# combine () and print () accept *literally* utf8 encoded data
	# parse () and getline () return *literally* utf8 encoded data

	$csv = Text::CSV::Encoded->new ({ encoding  => undef }); # default
	# combine () and print () accept UTF8 marked data
	# parse () and getline () return UTF8 marked data

       On combining ("print" and "combine"), if any of the combining fields was marked UTF8, the
       resulting string will be marked UTF8. Note however that all fields before the first field
       that was marked UTF8 and contained 8-bit characters that were not upgraded to UTF8, these
       will be bytes in the resulting string too, causing errors. If you pass data of different
       encoding, or you don't know if there is different encoding, force it to be upgraded before
       you pass them on:

	$csv->print ($fh, [ map { utf8::upgrade (my $x = $_); $x } @data ]);

       While no formal specification for CSV exists, RFC 4180 1) describes a common format and
       establishes "text/csv" as the MIME type registered with the IANA.

       Many informal documents exist that describe the CSV format. How To: The Comma Separated
       Value (CSV) File Format 2) provides an overview of the CSV format in the most widely used
       applications and explains how it can best be used and supported.

	1) http://tools.ietf.org/html/rfc4180
	2) http://www.creativyst.com/Doc/Articles/CSV/CSV01.htm

       The basic rules are as follows:

       CSV is a delimited data format that has fields/columns separated by the comma character
       and records/rows separated by newlines. Fields that contain a special character (comma,
       newline, or double quote), must be enclosed in double quotes.  However, if a line contains
       a single entry that is the empty string, it may be enclosed in double quotes. If a field's
       value contains a double quote character it is escaped by placing another double quote
       character next to it. The CSV file format does not require a specific character encoding,
       byte order, or line terminator format.

       o Each record is a single line ended by a line feed (ASCII/LF=0x0A) or a carriage return
	 and line feed pair (ASCII/CRLF=0x0D 0x0A), however, line-breaks may be embedded.

       o Fields are separated by commas.

       o 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.

       o A field within CSV must be surrounded by double-quotes to contain a the separator
	 character (comma).

       Though this is the most clear and restrictive definition, Text::CSV_XS is way more liberal
       than this, and allows extension:

       o Line termination by a single carriage return is accepted by default

       o The separation-, escape-, and escape- characters can be any ASCII character in the range
	 from 0x20 (space) to 0x7E (tilde). Characters outside this range may or may not work as
	 expected. Multibyte characters, like U+060c (ARABIC COMMA), U+FF0C (FULLWIDTH COMMA),
	 MARK), and U+201C (LEFT DOUBLE QUOTATION MARK) (to give some examples of what might look
	 promising) are therefor not allowed.

	 If you use perl-5.8.2 or higher, these three attributes are utf8-decoded, to increase
	 the likelihood of success. This way U+00FE will be allowed as a quote character.

       o 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.

       o Several violations of the above specification may be allowed by passing options to the
	 object creator.

       (Class method) Returns the current module version.

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

	my $csv = Text::CSV_XS->new ({ attributes ... });

       The following attributes are available:

       eol An end-of-line string to add to rows.

	   When not passed in a parser instance, the default behavior is to accept "\n", "\r",
	   and "\r\n", so it is probably safer to not specify "eol" at all. Passing "undef" or
	   the empty string behave the same.

	   Common values for "eol" are "\012" ("\n" or Line Feed), "\015\012" ("\r\n" or Carriage
	   Return, Line Feed), and "\015" ("\r" or Carriage Return). The "eol" attribute cannot
	   exceed 7 (ASCII) characters.

	   If both $/ and "eol" equal "\015", parsing lines that end on only a Carriage Return
	   without Line Feed, will be "parse"d correct.

	   The char used to separate 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.

	   See also "CAVEATS"

	   When this option is set to true, whitespace (TAB's and SPACE's) surrounding the
	   separation character is removed when parsing. If either TAB or SPACE is one of the
	   three major characters "sep_char", "quote_char", or "escape_char" it will not be
	   considered whitespace.

	   Now lines like:

	    1 , "foo" , bar , 3 , zapp

	   are correctly parsed, even though it violates the CSV specs.

	   Note that all whitespace is stripped from start and end of each field.  That would
	   make it more a feature than a way to enable parsing bad CSV lines, as

	    1,	 2.0,  3,   ape  , monkey

	   will now be parsed as

	    ("1", "2.0", "3", "ape", "monkey")

	   even if the original line was perfectly sane CSV.

	   Under normal circumstances, CSV data makes no distinction between quoted- and unquoted
	   empty fields. These both end up in an empty string field once read, thus

	    1,"",," ",2

	   is read as

	    ("1", "", "", " ", "2")

	   When writing CSV files with "always_quote" set, the unquoted empty field is the result
	   of an undefined value. To make it possible to also make this distinction when reading
	   CSV data, the "blank_is_undef" option will cause unquoted empty fields to be set to
	   undef, causing the above to be parsed as

	    ("1", "", undef, " ", "2")

	   Going one step further than "blank_is_undef", this attribute converts all empty fields
	   to undef, so

	    1,"",," ",2

	   is read as

	    (1, undef, undef, " ", 2)

	   Note that this effects only fields that are really empty, not fields that are empty
	   after stripping allowed whitespace. YMMV.

	   The character to quote 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,

	    1,foo "bar" baz,42

	   would result in a parse error. Though it is still bad practice to allow this format,
	   we cannot help the fact some vendors make their applications spit out lines styled
	   that way.

	   If there is really bad CSV data, like

	    1,"foo "bar" baz",42


	    1,""foo bar baz"",42

	   there is a way to get that parsed, and leave the quotes inside the quoted field as-is.
	   This can be achieved by setting "allow_loose_quotes" AND making sure that the
	   "escape_char" is not equal to "quote_char".

	   The character to escape 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:

	    "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_XS->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.

	   There is a backward compatibility issue in that the escape character, when differing
	   from the quotation character, cannot be on the first position of a field. e.g. with
	   "quote_char" equal to the default """ and "escape_char" set to "\", this would be


	   To overcome issues with backward compatibility, you can allow this by setting this
	   attribute to 1.

	   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.

	   If a string is marked UTF8, binary will be turned on automatically when binary
	   characters other than CR or NL are encountered. Note that a simple string like
	   "\x{00a0}" might still be binary, but not marked UTF8, so setting "{ binary =" 1 }> is
	   still a wise option.

	   A set of column types; this attribute is immediately passed to the "types" method. You
	   must not set this attribute otherwise, except for using the "types" method.

	   By default the generated fields are quoted only if they need to be. For example, if
	   they contain the separator character. If you set this attribute to a TRUE value, then
	   all defined fields will be quoted. ("undef" fields are not quoted, see
	   "blank_is_undef")). This is typically easier to handle in external applications. (Poor
	   creatures who are not using Text::CSV_XS. :-)

	   By default, a space in a field would trigger quotation. As no rule exists this to be
	   forced in CSV, nor any for the opposite, the default is true for safety. You can
	   exclude the space from this trigger by setting this attribute to 0.

	   By default, a NULL byte in a field would be escaped. This attribute enables you to
	   treat the NULL byte as a simple binary character in binary mode (the "{ binary => 1 }"
	   is set). The default is true.  You can prevent NULL escapes by setting this attribute
	   to 0.

	   By default,	all "unsafe" bytes inside a string cause the combined field to be quoted.
	   By setting this attribute to 0, you can disable that trigger for bytes >= 0x7f.

	   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 enable retrieving that information after parsing
	   with the methods "meta_info", "is_quoted", and "is_binary" described below.	Default
	   is false.

	   This is a quite controversial attribute to set, but it makes hard things possible.

	   The basic thought behind this is to tell the parser that the normally special
	   characters newline (NL) and Carriage Return (CR) will not be special when this flag is
	   set, and be dealt with as being ordinary binary characters. This will ease working
	   with data with embedded newlines.

	   When "verbatim" is used with "getline", "getline" auto-chomp's every line.

	   Imagine a file format like

	    M^^Hans^Janssen^Klas 2\n2A^Ja^11-06-2007#\r\n

	   where, the line ending is a very specific "#\r\n", and the sep_char is a ^ (caret).
	   None of the fields is quoted, but embedded binary data is likely to be present. With
	   the specific line ending, that should not be too hard to detect.

	   By default, Text::CSV_XS' parse function is instructed to only know about "\n" and
	   "\r" to be legal line endings, and so has to deal with the embedded newline as a real
	   end-of-line, so it can scan the next line if binary is true, and the newline is inside
	   a quoted field.  With this attribute, we tell parse () to parse the line as if "\n" is
	   just nothing more than a binary character.

	   For parse () this means that the parser has no idea about line ending anymore, and
	   getline () chomps line endings on reading.

	   Set to a true number between 1 and 9 will cause "error_diag" to be automatically be
	   called in void context upon errors.

	   In case of error "2012 - EOF", this call will be void.

	   If set to a value greater than 1, it will die on errors instead of warn.  If set to
	   anything unsupported, it will be silently ignored.

	   Future extensions to this feature will include more reliable auto-detection of the
	   "autodie" module being enabled, which will raise the value of "auto_diag" with 1 on
	   the moment the error is detected.

	   Set the verbosity of the "auto_diag" output. Currently only adds the current input
	   line (if known) to the diagnostic output with an indication of the position of the

       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,
	    quote_space 	  => 1,
	    quote_null		  => 1,
	    quote_binary	  => 1,
	    binary		  => 0,
	    keep_meta_info	  => 0,
	    allow_loose_quotes	  => 0,
	    allow_loose_escapes   => 0,
	    allow_unquoted_escape => 0,
	    allow_whitespace	  => 0,
	    blank_is_undef	  => 0,
	    empty_is_undef	  => 0,
	    verbatim		  => 0,
	    auto_diag		  => 0,
	    diag_verbose	  => 0,

       For all of the above mentioned flags, an accessor method is available where you can
       inquire 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.

       If the "new" constructor call fails, it returns "undef", and makes the fail reason
       available through the "error_diag" method.

	$csv = Text::CSV_XS->new ({ ecs_char => 1 }) or
	    die "".Text::CSV_XS->error_diag ();

       "error_diag" will return a string like

	"INI - Unknown attribute 'ecs_char'"

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

       Similar to "combine" + "string" + "print", but way more efficient. 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.

       For performance reasons the print method does not create a result string.  In particular
       the "string", "status", "fields", and "error_input" methods are meaningless after
       executing this method.

       If $colref is "undef" (explicit, not through a variable argument) and "bind_columns" was
       used to specify fields to be printed, it is possible to make performance improvements, as
       otherwise data would have to be copied as arguments to the method call:

	$csv->bind_columns (\($foo, $bar));
	$status = $csv->print ($fh, undef);

       A short benchmark

	my @data = ("aa" .. "zz");
	$csv->bind_columns (\(@data));

	$csv->print ($io, [ @data ]);	# 10800 recs/sec
	$csv->print ($io,  \@data  );	# 57100 recs/sec
	$csv->print ($io,   undef  );	# 50500 recs/sec

	$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.

	$line = $csv->string ();

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

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

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

       When fields are bound with "bind_columns", the return value is a reference to an empty

       The "string", "fields", and "status" methods are meaningless, again.

	$arrayref = $csv->getline_all ($io);
	$arrayref = $csv->getline_all ($io, $offset);
	$arrayref = $csv->getline_all ($io, $offset, $length);

       This will return a reference to a list of getline ($io) results.  In this call,
       "keep_meta_info" is disabled. If $offset is negative, as with "splice", only the last "abs
       ($offset)" records of $io are taken into consideration.

       Given a CSV file with 10 lines:

	lines call
	----- ---------------------------------------------------------
	0..9  $csv->getline_all ($io)	      # all
	0..9  $csv->getline_all ($io,  0)     # all
	8..9  $csv->getline_all ($io,  8)     # start at 8
	-     $csv->getline_all ($io,  0,  0) # start at 0 first 0 rows
	0..4  $csv->getline_all ($io,  0,  5) # start at 0 first 5 rows
	4..5  $csv->getline_all ($io,  4,  2) # start at 4 first 2 rows
	8..9  $csv->getline_all ($io, -2)     # last 2 rows
	6..7  $csv->getline_all ($io, -4,  2) # first 2 of last  4 rows

	$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 "types"' description below.

       The "getline_hr" and "column_names" methods work together to allow you to have rows
       returned as hashrefs. You must call "column_names" first to declare your column names.

	$csv->column_names (qw( code name price description ));
	$hr = $csv->getline_hr ($io);
	print "Price for $hr->{name} is $hr->{price} EUR\n";

       "getline_hr" will croak if called before "column_names".

       Note that "getline_hr" creates a hashref for every row and will be much slower than the
       combined use of "bind_columns" and "getline" but still offering the same ease of use
       hashref inside the loop:

	my @cols = @{$csv->getline ($io)};
	$csv->column_names (@cols);
	while (my $row = $csv->getline_hr ($io)) {
	    print $row->{price};

       Could easily be rewritten to the much faster:

	my @cols = @{$csv->getline ($io)};
	my $row = {};
	$csv->bind_columns (\@{$row}{@cols});
	while ($csv->getline ($io)) {
	    print $row->{price};

       Your mileage may vary for the size of the data and the number of rows. With perl-5.14.2
       the comparison for a 100_000 line file with 14 rows:

		   Rate hashrefs getlines
	hashrefs 1.00/s       --     -76%
	getlines 4.15/s     313%       --

	$arrayref = $csv->getline_hr_all ($io);
	$arrayref = $csv->getline_hr_all ($io, $offset);
	$arrayref = $csv->getline_hr_all ($io, $offset, $length);

       This will return a reference to a list of getline_hr ($io) results.  In this call,
       "keep_meta_info" is disabled.

	$csv->print_hr ($io, $ref);

       Provides an easy way to print a $ref as fetched with getline_hr provided the column names
       are set with column_names.

       It is just a wrapper method with basic parameter checks over

	$csv->print ($io, [ map { $ref->{$_} } $csv->column_names ]);

       Set the keys that will be used in the "getline_hr" calls. If no keys (column names) are
       passed, it'll return the current setting.

       "column_names" accepts a list of scalars (the column names) or a single array_ref, so you
       can pass "getline"

	$csv->column_names ($csv->getline ($io));

       "column_names" does no checking on duplicates at all, which might lead to unwanted
       results. Undefined entries will be replaced with the string "\cAUNDEF\cA", so

	$csv->column_names (undef, "", "name", "name");
	$hr = $csv->getline_hr ($io);

       Will set "$hr->{"\cAUNDEF\cA"}" to the 1st field, "$hr->{""}" to the 2nd field, and
       "$hr->{name}" to the 4th field, discarding the 3rd field.

       "column_names" croaks on invalid arguments.

       Takes a list of references to scalars to be printed with "print" or to store the fields
       fetched by "getline" in. When you don't pass enough references to store the fetched fields
       in, "getline" will fail. If you pass more than there are fields to return, the remaining
       references are left untouched.

	$csv->bind_columns (\$code, \$name, \$price, \$description);
	while ($csv->getline ($io)) {
	    print "The price of a $name is \x{20ac} $price\n";

       To reset or clear all column binding, call "bind_columns" with a single argument "undef".
       This will also clear column names.

	$csv->bind_columns (undef);

       If no arguments are passed at all, "bind_columns" will return the list current bindings or
       "undef" if no binds are active.

	$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.

	$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.

	@columns = $csv->fields ();

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

       Note that the return value is undefined after using "getline", which does not fill the
       data structures returned by "parse".

	@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 bit-wise-
       or'd like:

       " "0x0001
	 The field was quoted.

       " "0x0002
	 The field was binary.

       See the "is_***" methods below.

	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.

	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]".

	my $missing = $csv->is_missing ($column_idx);

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

	while (my $hr = $csv->getline_hr ($fh)) {
	    $csv->is_missing (0) and next; # This was an empty line

       When using "getline_hr" for parsing, it is impossible to tell if the fields are "undef"
       because they where not filled in the CSV stream or because they were not read at all, as
       all the fields defined by "column_names" are set in the hash-ref. If you still need to
       know if all fields in each row are provided, you should enable "keep_meta_info" so you can
       check the flags.

	$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. If the last call was successful,
       "error_input" will return "undef".

	Text::CSV_XS->error_diag ();
	$csv->error_diag ();
	$error_code	      = 0  + $csv->error_diag ();
	$error_str	      = "" . $csv->error_diag ();
	($cde, $str, $pos, $recno) = $csv->error_diag ();

       If (and only if) an error occurred, 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 the last error was from parsing, the third value returned is a best guess at the
       location within the line that was being parsed. Its value is 1-based. The forth value
       represents the record count parsed by this csv object See examples/csv-check for how this
       can be used.

       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

       When called as a class method or a direct function call, the error diagnostics is that of
       the last "new" call.

	$recno = $csv->record_number ();

       Returns the records parsed by this csv instance. This value should be more accurate than
       $. when embedded newlines come in play. Records written by this instance are not counted.

	$csv->SetDiag (0);

       Use to reset the diagnostics if you are dealing with errors.

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

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

   Reading a CSV file line by line:
	my $csv = Text::CSV_XS->new ({ binary => 1 });
	open my $fh, "<", "file.csv" or die "file.csv: $!";
	while (my $row = $csv->getline ($fh)) {
	    # do something with @$row
	$csv->eof or $csv->error_diag;
	close $fh or die "file.csv: $!";

   Parsing CSV strings:
	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 {
	    print STDERR "parse () failed on argument: ",
		$csv->error_input, "\n";
	    $csv->error_diag ();

   Printing CSV data
       The fast way: using "print"

       An example for creating CSV files using the "print" method, like in dumping the content of
       a database ($dbh) table ($tbl) to CSV:

	my $csv = Text::CSV_XS->new ({ binary => 1, eol => $/ });
	open my $fh, ">", "$tbl.csv" or die "$tbl.csv: $!";
	my $sth = $dbh->prepare ("select * from $tbl");
	$csv->print ($fh, $sth->{NAME_lc});
	while (my $row = $sth->fetch) {
	    $csv->print ($fh, $row) or $csv->error_diag;
	close $fh or die "$tbl.csv: $!";

       The slow way: using "combine" and "string"

       or using the slower "combine" and "string" methods:

	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)) {
	    print $csv_fh $csv->string, "\n";
	else {
	    print "combine () failed on argument: ",
		$csv->error_input, "\n";
	close $csv_fh or die "hello.csv: $!";

   The examples folder
       For more extended examples, see the examples/ (1) sub-directory in the original
       distribution or the git repository (2).

	1. http://repo.or.cz/w/Text-CSV_XS.git?a=tree;f=examples
	2. http://repo.or.cz/w/Text-CSV_XS.git

       The following files can be found there:

	 This can be used as a boilerplate to `fix' bad CSV and parse beyond errors.

	  $ perl examples/parser-xs.pl bad.csv >good.csv

	 This is a command-line tool that uses parser-xs.pl techniques to check the CSV file and
	 report on its content.

	  $ csv-check files/utf8.csv
	  Checked with examples/csv-check 1.5 using Text::CSV_XS 0.81
	  OK: rows: 1, columns: 2
	      sep = <,>, quo = <">, bin = <1>

	 A script to convert CSV to Microsoft Excel. This requires Date::Calc and
	 Spreadsheet::WriteExcel. The converter accepts various options and can produce UTF-8
	 Excel files.

	 A script that provides colorized diff on sorted CSV files, assuming first line is header
	 and first field is the key. Output options include colorized ANSI escape codes or HTML.

	  $ csvdiff --html --output=diff.html file1.csv file2.csv

       "Text::CSV_XS" is not designed to detect the characters used to quote and separate fields.
       The parsing is done using predefined settings. In the examples sub-directory, you can find
       scripts that demonstrate how you can try to detect these characters yourself.

   Microsoft Excel
       The import/export from Microsoft Excel is a risky task, according to the documentation in
       "Text::CSV::Separator". Microsoft uses the system's default list separator defined in the
       regional settings, which happens to be a semicolon for Dutch, German and Spanish (and
       probably some others as well).  For the English locale, the default is a comma. In Windows
       however, the user is free to choose a predefined locale, and then change every individual
       setting in it, so checking the locale is no solution.

       More Errors & Warnings
	 New extensions ought to be clear and concise in reporting what error occurred where and
	 why, and possibly also tell a remedy to the problem.  error_diag is a (very) good start,
	 but there is more work to be done here.

	 Basic calls should croak or warn on illegal parameters. Errors should be documented.

       setting meta info
	 Future extensions might include extending the "meta_info", "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 the whole file at once
	 Implement new methods that enable parsing of a complete file at once, returning a list
	 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  => [ ... ],
	    { fields => [ ... ],

	 Note that "getline_all" already returns all rows for an open stream, but this will not
	 return flags.

       combined methods
	 Requests for adding means (methods) that combine "combine" and "string" in a single call
	 will not be honored. Likewise for "parse" and "fields". Given the trouble with embedded
	 newlines, using "getline" and "print" instead is the preferred way to go.

   Release plan
       No guarantees, but this is what I had in mind some time ago:

	  - This might very well be 1.00
	  - DIAGNOSTICS setction in pod to *describe* the errors (see below)
	  - croak / carp

       next + 1
	  - csv2csv - a script to regenerate a CSV file to follow standards

       The hard-coding of characters and character ranges makes this module unusable on EBCDIC

       Opening EBCDIC encoded files on ASCII+ systems is likely to succeed using Encode's cp37,
       cp1047, or posix-bc:

	open my $fh, "<:encoding(cp1047)", "ebcdic_file.csv" or die "...";

       Still under construction ...

       If an error occurred, "$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
       occurred - may cause unexpected results.

       If the constructor failed, the cause can be found using "error_diag" as a class method,
       like "Text::CSV_XS-"error_diag>.

       "$csv-"error_diag> is automatically called upon error when the contractor was called with
       "auto_diag" set to 1 or 2, or when "autodie" is in effect.  When set to 1, this will cause
       a "warn" with the error message, when set to 2, it will "die". "2012 - EOF" is excluded
       from "auto_diag" reports.

       The errors as described below are available. I have tried to make the error itself
       explanatory enough, but more descriptions will be added. For most of these errors, the
       first three capitals describe the error category:

       o INI

	 Initialization error or option conflict.

       o ECR

	 Carriage-Return related parse error.

       o EOF

	 End-Of-File related parse error.

       o EIQ

	 Parse error inside quotation.

       o EIF

	 Parse error inside field.

       o ECB

	 Combine error.

       o EHR

	 HashRef parse related error.

       And below should be the complete list of error codes that can be returned:

       o 1001 "INI - sep_char is equal to quote_char or escape_char"

	 The separation character cannot be equal to either the quotation character or the escape
	 character, as that will invalidate all parsing rules.

       o 1002 "INI - allow_whitespace with escape_char or quote_char SP or TAB"

	 Using "allow_whitespace" when either "escape_char" or "quote_char" is equal to SPACE or
	 TAB is too ambiguous to allow.

       o 1003 "INI - \r or \n in main attr not allowed"

	 Using default "eol" characters in either "sep_char", "quote_char", or "escape_char" is
	 not allowed.

       o 2010 "ECR - QUO char inside quotes followed by CR not part of EOL"

	 When "eol" has been set to something specific, other than the default, like "\r\t\n",
	 and the "\r" is following the second (closing) "quote_char", where the characters
	 following the "\r" do not make up the "eol" sequence, this is an error.

       o 2011 "ECR - Characters after end of quoted field"

	 Sequences like "1,foo,"bar"baz,2" are not allowed. "bar" is a quoted field, and after
	 the closing quote, there should be either a new-line sequence or a separation character.

       o 2012 "EOF - End of data in parsing input stream"

	 Self-explaining. End-of-file while inside parsing a stream. Can happen only when reading
	 from streams with "getline", as using "parse" is done on strings that are not required
	 to have a trailing "eol".

       o 2021 "EIQ - NL char inside quotes, binary off"

	 Sequences like "1,"foo\nbar",2" are allowed only when the binary option has been
	 selected with the constructor.

       o 2022 "EIQ - CR char inside quotes, binary off"

	 Sequences like "1,"foo\rbar",2" are allowed only when the binary option has been
	 selected with the constructor.

       o 2023 "EIQ - QUO character not allowed"

	 Sequences like ""foo "bar" baz",quux" and "2023,",2008-04-05,"Foo, Bar",\n" will cause
	 this error.

       o 2024 "EIQ - EOF cannot be escaped, not even inside quotes"

	 The escape character is not allowed as last character in an input stream.

       o 2025 "EIQ - Loose unescaped escape"

	 An escape character should escape only characters that need escaping.	Allowing the
	 escape for other characters is possible with the "allow_loose_escape" attribute.

       o 2026 "EIQ - Binary character inside quoted field, binary off"

	 Binary characters are not allowed by default. Exceptions are fields that contain valid
	 UTF-8, that will automatically be upgraded is the content is valid UTF-8. Pass the
	 "binary" attribute with a true value to accept binary characters.

       o 2027 "EIQ - Quoted field not terminated"

	 When parsing a field that started with a quotation character, the field is expected to
	 be closed with a quotation character. When the parsed line is exhausted before the quote
	 is found, that field is not terminated.

       o 2030 "EIF - NL char inside unquoted verbatim, binary off"

       o 2031 "EIF - CR char is first char of field, not part of EOL"

       o 2032 "EIF - CR char inside unquoted, not part of EOL"

       o 2034 "EIF - Loose unescaped quote"

       o 2035 "EIF - Escaped EOF in unquoted field"

       o 2036 "EIF - ESC error"

       o 2037 "EIF - Binary character in unquoted field, binary off"

       o 2110 "ECB - Binary character in Combine, binary off"

       o 2200 "EIO - print to IO failed. See errno"

       o 3001 "EHR - Unsupported syntax for column_names ()"

       o 3002 "EHR - getline_hr () called before column_names ()"

       o 3003 "EHR - bind_columns () and column_names () fields count mismatch"

       o 3004 "EHR - bind_columns () only accepts refs to scalars"

       o 3006 "EHR - bind_columns () did not pass enough refs for parsed fields"

       o 3007 "EHR - bind_columns needs refs to writable scalars"

       o 3008 "EHR - unexpected error in bound fields"

       o 3009 "EHR - print_hr () called before column_names ()"

       o 3010 "EHR - print_hr () called with invalid arguments"

       perl, IO::File, IO::Handle, IO::Wrap, Text::CSV, Text::CSV_PP, Text::CSV::Encoded,
       Text::CSV::Separator, and Spreadsheet::Read.

       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 that 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

       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
       and added all the allow flags. See ChangeLog releases 0.25 and on.

	Copyright (C) 2007-2013 H.Merijn Brand.  All rights reserved.
	Copyright (C) 1998-2001 Jochen Wiedmann. All rights reserved.
	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.

perl v5.16.3				    2013-06-13					CSV_XS(3)

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