Provided by: libtext-csv-xs-perl_1.34-1_amd64 bug

NAME

       Text::CSV_XS - comma-separated values manipulation routines

SYNOPSIS

        # Functional interface
        use Text::CSV_XS qw( csv );

        # Read whole file in memory
        my $aoa = csv (in => "data.csv");    # as array of array
        my $aoh = csv (in => "data.csv",
                       headers => "auto");   # as array of hash

        # Write array of arrays as csv file
        csv (in => $aoa, out => "file.csv", sep_char=> ";");

        # Only show lines where "code" is odd
        csv (in => "data.csv", filter => { code => sub { $_ % 2 }});

        # Object interface
        use Text::CSV_XS;

        my @rows;
        # Read/parse CSV
        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;

        # and write as CSV
        open $fh, ">:encoding(utf8)", "new.csv" or die "new.csv: $!";
        $csv->say ($fh, $_) for @rows;
        close $fh or die "new.csv: $!";

DESCRIPTION

       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 the 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 ();
            }

       this will break, as the "while" might read broken lines:  it 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 $fh, "<", $file or die "$file: $!";
        while (my $row = $csv->getline ($fh)) {
            my @fields = @$row;
            }

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

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

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

       See also "BOM".

       The simplest way to ensure the correct encoding is used for  in- and output is by either setting layers
       on the filehandles, or setting the "encoding" argument for "csv".

        open my $fh, "<:encoding(UTF-8)", "in.csv"  or die "in.csv: $!";
       or
        my $aoa = csv (in => "in.csv",     encoding => "UTF-8");

        open my $fh, ">:encoding(UTF-8)", "out.csv" or die "out.csv: $!";
       or
        csv (in => $aoa, out => "out.csv", encoding => "UTF-8");

       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.

       On combining ("print"  and  "combine"):  if any of the combining fields was marked UTF8, the resulting
       string will be marked as UTF8.  Note however that all fields  before  the first field marked UTF8 and
       contained 8-bit characters that were not upgraded to UTF8,  these will be  "bytes"  in the resulting
       string too, possibly causing unexpected 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 ]);

       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

   BOM
       BOM  (or Byte Order Mark)  handling is available only inside the "header" method.   This method supports
       the following encodings: "utf-8", "utf-1", "utf-32be", "utf-32le", "utf-16be", "utf-16le", "utf-ebcdic",
       "scsu", "bocu-1", and "gb-18030". See Wikipedia <https://en.wikipedia.org/wiki/Byte_order_mark>.

       If a file has a BOM, the easiest way to deal with that is

        my $aoh = csv (in => $file, detect_bom => 1);

       All records will be encoded based on the detected BOM.

       This implies a call to the  "header"  method,  which defaults to also set the "column_names". So this is
       not the same as

        my $aoh = csv (in => $file, headers => "auto");

       which only reads the first record to set  "column_names"  but ignores any meaning of possible present
       BOM.

SPECIFICATION

       While no formal specification for CSV exists, RFC 4180 <http://tools.ietf.org/html/rfc4180> (1) describes
       the common format and establishes  "text/csv" as the MIME type registered with the IANA. RFC 7111
       <http://tools.ietf.org/html/rfc7111> (2) adds fragments to CSV.

       Many informal documents exist that describe the "CSV" format.   "How To: The Comma Separated Value (CSV)
       File Format" <http://www.creativyst.com/Doc/Articles/CSV/CSV01.htm> (3)  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://tools.ietf.org/html/rfc7111
        3) 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.

       • 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.

       • Fields are separated by commas.

       • 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"  must be surrounded by  double-quotes to  contain  a separator character (comma).

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

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

       • 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  UTF  "U+060C"  (ARABIC  COMMA),    "U+FF0C" (FULLWIDTH COMMA),  "U+241B" (SYMBOL FOR
         ESCAPE), "U+2424" (SYMBOL FOR NEWLINE), "U+FF02" (FULLWIDTH QUOTATION MARK), and "U+201C" (LEFT  DOUBLE
         QUOTATION  MARK)  (to  give some examples of what might look promising) work for newer versions of perl
         for "sep_char", and "quote_char" but not for "escape_char".

         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.

       • A field in  "CSV"  must be surrounded by double-quotes to make an embedded double-quote, represented by
         a  pair of consecutive double-quotes, valid. In binary mode you may additionally use the sequence  ""0"
         for representation of a NULL byte. Using 0x00 in binary mode is just as valid.

       • Several violations of the above specification may be lifted by passing some options  as  attributes  to
         the object constructor.

METHODS

   version
       (Class method) Returns the current module version.

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

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

       The following attributes are available:

       eol

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

       The end-of-line string to add to rows for "print" or the record separator for "getline".

       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.

       When not passed in a generating instance,  records are not terminated at all, so it is probably  wise  to
       pass something you expect. A safe choice for "eol" on output is either $/ or "\r\n".

       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.

       sep_char

        my $csv = Text::CSV_XS->new ({ sep_char => ";" });
                $csv->sep_char (";");
        my $c = $csv->sep_char;

       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). When longer sequences are required, use "sep".

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

       See also "CAVEATS"

       sep

        my $csv = Text::CSV_XS->new ({ sep => "\N{FULLWIDTH COMMA}" });
                  $csv->sep (";");
        my $sep = $csv->sep;

       The chars used to separate fields, by default undefined. Limited to 8 bytes.

       When set, overrules "sep_char".  If its length is one byte it acts as an alias to "sep_char".

       See also "CAVEATS"

       quote_char

        my $csv = Text::CSV_XS->new ({ quote_char => "'" });
                $csv->quote_char (undef);
        my $c = $csv->quote_char;

       The  character  to  quote fields containing blanks or binary data,  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).  When longer sequences are required,
       use "quote".

       "quote_char" can not be equal to "sep_char".

       quote

        my $csv = Text::CSV_XS->new ({ quote => "\N{FULLWIDTH QUOTATION MARK}" });
                    $csv->quote ("'");
        my $quote = $csv->quote;

       The chars used to quote fields, by default undefined. Limited to 8 bytes.

       When set, overrules "quote_char". If its length is one byte it acts as an alias to "quote_char".

       See also "CAVEATS"

       escape_char

        my $csv = Text::CSV_XS->new ({ escape_char => "\\" });
                $csv->escape_char (":");
        my $c = $csv->escape_char;

       The  character  to   escape   certain characters inside quoted fields.  This is limited to a  single-byte
       character,  usually  in the  range from  0x20 (space) to 0x7E (tilde).

       The "escape_char" defaults to being the 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   "quote_char"  without  changing  the "escape_char",  the  "escape_char" will still
       be  the double-quote (""").  If instead you want to escape the  "quote_char" by doubling it you will need
       to also change the  "escape_char"  to be the same as what you have changed the "quote_char" to.

       Setting "escape_char" to <undef> or "" will disable escaping completely and is greatly discouraged.  This
       will also disable "escape_null".

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

       binary

        my $csv = Text::CSV_XS->new ({ binary => 1 });
                $csv->binary (0);
        my $f = $csv->binary;

       If  this  attribute is 1,  you may use binary characters in quoted fields, including line feeds, carriage
       returns and "NULL" bytes. (The latter could 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" and "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.

       strict

        my $csv = Text::CSV_XS->new ({ strict => 1 });
                $csv->strict (0);
        my $f = $csv->strict;

       If  this attribute is set to 1, any row that parses to a different number of fields than the previous row
       will cause the parser to throw error 2014.

       formula_handling

       formula

        my $csv = Text::CSV_XS->new ({ formula => "none" });
                $csv->formula ("none");
        my $f = $csv->formula;

       This defines the behavior of  fields  containing  formulas.  As  formulas  are  considered  dangerous  in
       spreadsheets,  this  attribute  can define an optional action to be taken if a field starts with an equal
       sign ("=").

       For purpose of code-readability, this can also be written as

        my $csv = Text::CSV_XS->new ({ formula_handling => "none" });
                $csv->formula_handling ("none");
        my $f = $csv->formula_handling;

       Possible values for this attribute are

       none
         Take no specific action. This is the default.

          $csv->formula ("none");

       die
         Cause the process to "die" whenever a leading "=" is encountered.

          $csv->formula ("die");

       croak
         Cause the process to "croak" whenever a leading "=" is encountered.  (See Carp)

          $csv->formula ("croak");

       diag
         Report position and content of the field whenever a leading  "=" is found.  The value of the  field  is
         unchanged.

          $csv->formula ("diag");

       empty
         Replace the content of fields that start with a "=" with the empty string.

          $csv->formula ("empty");
          $csv->formula ("");

       undef
         Replace the content of fields that start with a "=" with "undef".

          $csv->formula ("undef");
          $csv->formula (undef);

       All other values will give a warning and then fallback to "diag".

       decode_utf8

        my $csv = Text::CSV_XS->new ({ decode_utf8 => 1 });
                $csv->decode_utf8 (0);
        my $f = $csv->decode_utf8;

       This attributes defaults to TRUE.

       While parsing,  fields that are valid UTF-8, are automatically set to be UTF-8, so that

         $csv->parse ("\xC4\xA8\n");

       results in

         PV("\304\250"\0) [UTF8 "\x{128}"]

       Sometimes  it might not be a desired action.  To prevent those upgrades, set this attribute to false, and
       the result will be

         PV("\304\250"\0)

       auto_diag

        my $csv = Text::CSV_XS->new ({ auto_diag => 1 });
                $csv->auto_diag (2);
        my $l = $csv->auto_diag;

       Set this attribute to a number between 1 and 9 causes  "error_diag" to be automatically  called  in  void
       context upon errors.

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

       If  "auto_diag"  is set to a numeric value greater than 1, it will "die" on errors instead of "warn".  If
       set to anything unrecognized,  it will be silently ignored.

       Future extensions to this feature will include more reliable auto-detection of  "autodie"   being  active
       in the scope of which the error occurred which will increment the value of "auto_diag" with  1 the moment
       the error is detected.

       diag_verbose

        my $csv = Text::CSV_XS->new ({ diag_verbose => 1 });
                $csv->diag_verbose (2);
        my $l = $csv->diag_verbose;

       Set  the  verbosity  of  the  output  triggered by "auto_diag".   Currently only adds the current  input-
       record-number  (if known)  to the diagnostic output with an indication of the position of the error.

       blank_is_undef

        my $csv = Text::CSV_XS->new ({ blank_is_undef => 1 });
                $csv->blank_is_undef (0);
        my $f = $csv->blank_is_undef;

       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 either  "always_quote" or  "quote_empty" set, the unquoted  empty field is
       the  result  of  an  undefined  value.    To  enable  this  distinction  when   reading "CSV"  data,  the
       "blank_is_undef"  attribute will cause  unquoted empty fields to be set to "undef", causing the above  to
       be parsed as

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

       note  that  this  is specifically important when loading  "CSV" fields into a database that allows "NULL"
       values,  as the perl equivalent for "NULL" is "undef" in DBI land.

       empty_is_undef

        my $csv = Text::CSV_XS->new ({ empty_is_undef => 1 });
                $csv->empty_is_undef (0);
        my $f = $csv->empty_is_undef;

       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   originally   empty,  not fields that are empty after
       stripping allowed whitespace. YMMV.

       allow_whitespace

        my $csv = Text::CSV_XS->new ({ allow_whitespace => 1 });
                $csv->allow_whitespace (0);
        my $f = $csv->allow_whitespace;

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

       Now lines like:

        1 , "foo" , bar , 3 , zapp

       are parsed as valid "CSV", even though it violates the "CSV" specs.

       Note that  all  whitespace is stripped from both  start and  end of each field.  That would make it  more
       than a feature 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 acceptable "CSV".

       allow_loose_quotes

        my $csv = Text::CSV_XS->new ({ allow_loose_quotes => 1 });
                $csv->allow_loose_quotes (0);
        my $f = $csv->allow_loose_quotes;

       By default, parsing unquoted fields containing "quote_char" characters like

        1,foo "bar" baz,42

       would result in parse error 2034.  Though it is still bad practice to  allow  this  format,   we   cannot
       help  the  fact  that  some  vendors  make  their applications spit out lines styled this way.

       If there is really bad "CSV" data, like

        1,"foo "bar" baz",42

       or

        1,""foo bar baz"",42

       there is a way to get this data-line 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".

       allow_loose_escapes

        my $csv = Text::CSV_XS->new ({ allow_loose_escapes => 1 });
                $csv->allow_loose_escapes (0);
        my $f = $csv->allow_loose_escapes;

       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  parse  error  2025.    Though it is bad practice to allow this format,  this attribute
       enables you to treat all escape character sequences equal.

       allow_unquoted_escape

        my $csv = Text::CSV_XS->new ({ allow_unquoted_escape => 1 });
                $csv->allow_unquoted_escape (0);
        my $f = $csv->allow_unquoted_escape;

       A backward compatibility issue where "escape_char" differs from "quote_char"  prevents  "escape_char"  to
       be  in  the  first position of a field.  If "quote_char" is equal to the default """ and "escape_char" is
       set to "\", this would be illegal:

        1,\0,2

       Setting this attribute to 1  might help to overcome issues with backward  compatibility  and  allow  this
       style.

       always_quote

        my $csv = Text::CSV_XS->new ({ always_quote => 1 });
                $csv->always_quote (0);
        my $f = $csv->always_quote;

       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 1 then all defined  fields  will  be  quoted.  ("undef"
       fields are not quoted, see "blank_is_undef"). This makes it quite often easier to handle exported data in
       external applications.   (Poor creatures who are better to use Text::CSV_XS. :)

       quote_space

        my $csv = Text::CSV_XS->new ({ quote_space => 1 });
                $csv->quote_space (0);
        my $f = $csv->quote_space;

       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.

       quote_empty

        my $csv = Text::CSV_XS->new ({ quote_empty => 1 });
                $csv->quote_empty (0);
        my $f = $csv->quote_empty;

       By  default  the generated fields are quoted only if they need to be.   An empty (defined) field does not
       need quotation. If you set this attribute to 1 then empty defined fields will be quoted.  ("undef" fields
       are not quoted, see "blank_is_undef"). See also "always_quote".

       quote_binary

        my $csv = Text::CSV_XS->new ({ quote_binary => 1 });
                $csv->quote_binary (0);
        my $f = $csv->quote_binary;

       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.

       escape_null

        my $csv = Text::CSV_XS->new ({ escape_null => 1 });
                $csv->escape_null (0);
        my $f = $csv->escape_null;

       By default, a "NULL" byte in a field would be escaped. This option 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.

       When the "escape_char" attribute is set to undefined,  this attribute will be set to false.

       The default setting will encode "=\x00=" as

        "="0="

       With "escape_null" set, this will result in

        "=\x00="

       The default when using the "csv" function is "false".

       For backward compatibility reasons,  the deprecated old name  "quote_null" is still recognized.

       keep_meta_info

        my $csv = Text::CSV_XS->new ({ keep_meta_info => 1 });
                $csv->keep_meta_info (0);
        my $f = $csv->keep_meta_info;

       By default, the parsing of input records is as simple and  fast  as  possible.   However,   some  parsing
       information  - like quotation of the original field - is lost in that process.  Setting this flag to true
       enables retrieving that information after parsing  with   the  methods   "meta_info",   "is_quoted",  and
       "is_binary" described below.  Default is false for performance.

       If  you  set this attribute to a value greater than 9,   than you can control output quotation style like
       it was used in the input of the the last parsed record (unless  quotation  was  added  because  of  other
       reasons).

        my $csv = Text::CSV_XS->new ({
           binary         => 1,
           keep_meta_info => 1,
           quote_space    => 0,
           });

        my $row = $csv->parse (q{1,,"", ," ",f,"g","h""h",help,"help"});

        $csv->print (*STDOUT, \@row);
        # 1,,, , ,f,g,"h""h",help,help
        $csv->keep_meta_info (11);
        $csv->print (*STDOUT, \@row);
        # 1,,"", ," ",f,"g","h""h",help,"help"

       verbatim

        my $csv = Text::CSV_XS->new ({ verbatim => 1 });
                $csv->verbatim (0);
        my $f = $csv->verbatim;

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

       The  rationale  behind  this attribute 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, this
       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 option, 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 more idea about line ending and "getline" "chomp"s line
       endings on reading.

       types

       A set of column types; the attribute is immediately passed to the "types" method.

       callbacks

       See the "Callbacks" section below.

       accessors

       To sum it up,

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

       is equivalent to

        $csv = Text::CSV_XS->new ({
            eol                   => undef, # \r, \n, or \r\n
            sep_char              => ',',
            sep                   => undef,
            quote_char            => '"',
            quote                 => undef,
            escape_char           => '"',
            binary                => 0,
            decode_utf8           => 1,
            auto_diag             => 0,
            diag_verbose          => 0,
            blank_is_undef        => 0,
            empty_is_undef        => 0,
            allow_whitespace      => 0,
            allow_loose_quotes    => 0,
            allow_loose_escapes   => 0,
            allow_unquoted_escape => 0,
            always_quote          => 0,
            quote_empty           => 0,
            quote_space           => 1,
            escape_null           => 1,
            quote_binary          => 1,
            keep_meta_info        => 0,
            verbatim              => 0,
            types                 => undef,
            callbacks             => undef,
            });

       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  not  wise 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'"

   known_attributes
        @attr = Text::CSV_CS->known_attributes;
        @attr = Text::CSV_CS::known_attributes;
        @attr = $csv->known_attributes;

       This  method  will return an ordered list of all the supported  attributes as described above.   This can
       be useful for knowing what attributes are valid in classes that use or extend Text::CSV_XS.

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

       Similar to  "combine" + "string" + "print",  but much 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  $fh
       object, typically an IO handle or any other object that offers a "print" method.

       For  performance reasons  "print"  does not create a result string,  so all "string", "status", "fields",
       and "error_input" methods will return undefined information 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));

        $csv->print ($fh, [ @data ]);   # 11800 recs/sec
        $csv->print ($fh,  \@data  );   # 57600 recs/sec
        $csv->print ($fh,   undef  );   # 48500 recs/sec

   say
        $status = $csv->say ($fh, $colref);

       Like "print", but "eol" defaults to "$\".

   print_hr
        $csv->print_hr ($fh, $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

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

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

       This  method constructs a "CSV" record from  @fields,  returning success or failure.   Failure can result
       from lack of arguments or an argument that contains 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" could be called to retrieve the invalid argument.

   string
        $line = $csv->string ();

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

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

       This  is the counterpart to  "print",  as "parse"  is the counterpart to "combine":  it parses a row from
       the $fh  handle using the "getline" method associated with $fh  and parses this row into  an  array  ref.
       This  array ref is returned by the function or "undef" for failure.  When $fh does not support "getline",
       you are likely to hit errors.

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

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

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

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

       Given a CSV file with 10 lines:

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

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

       Could easily be rewritten to the much faster:

        my @cols = @{$csv->getline ($fh)};
        my $row = {};
        $csv->bind_columns (\@{$row}{@cols});
        while ($csv->getline ($fh)) {
            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%       --

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

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

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

       This  method 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 calling "fields" will return undefined data 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 $line argument is supposed to be a simple scalar. Everything else is supposed to croak and set  error
       1500.

   fragment
       This  function  tries  to  implement  RFC7111   (URI  Fragment Identifiers for the text/csv Media Type) -
       http://tools.ietf.org/html/rfc7111

        my $AoA = $csv->fragment ($fh, $spec);

       In specifications,  "*" is used to specify the last item, a dash ("-") to indicate a range.   All indices
       are 1-based:  the first row or column has index 1. Selections can be combined with the semi-colon (";").

       When using this method in combination with  "column_names",  the returned  reference   will  point  to  a
       list  of  hashes  instead of a  list of lists.  A disjointed  cell-based combined selection  might return
       rows with different number of columns making the use of hashes unpredictable.

        $csv->column_names ("Name", "Age");
        my $AoH = $csv->fragment ($fh, "col=3;8");

       If the "after_parse" callback is active,  it is also called on every line parsed and skipped  before  the
       fragment.

       row
          row=4
          row=5-7
          row=6-*
          row=1-2;4;6-*

       col
          col=2
          col=1-3
          col=4-*
          col=1-2;4;7-*

       cell
         In cell-based selection, the comma (",") is used to pair row and column

          cell=4,1

         The range operator ("-") using "cell"s can be used to define top-left and bottom-right "cell" location

          cell=3,1-4,6

         The "*" is only allowed in the second part of a pair

          cell=3,2-*,2    # row 3 till end, only column 2
          cell=3,2-3,*    # column 2 till end, only row 3
          cell=3,2-*,*    # strip row 1 and 2, and column 1

         Cells  and  cell  ranges  may be combined with ";", possibly resulting in rows with different number of
         columns

          cell=1,1-2,2;3,3-4,4;1,4;4,1

         Disjointed selections will only return selected cells.   The cells that are not  specified   will   not
         be  included  in the  returned set,  not even as "undef".  As an example given a "CSV" like

          11,12,13,...19
          21,22,...28,29
          :            :
          91,...97,98,99

         with "cell=1,1-2,2;3,3-4,4;1,4;4,1" will return:

          11,12,14
          21,22
          33,34
          41,43,44

         Overlapping  cell-specs  will  return  those  cells  only  once, So "cell=1,1-3,3;2,2-4,4;2,3;4,2" will
         return:

          11,12,13
          21,22,23,24
          31,32,33,34
          42,43,44

       RFC7111 <http://tools.ietf.org/html/rfc7111> does  not  allow different types of  specs  to  be  combined
       (either  "row"  or  "col" or "cell").  Passing an invalid fragment specification will croak and set error
       2013.

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

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

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

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

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

       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.

   header
       This method does NOT work in perl-5.6.x

       Parse the CSV header and set "sep", column_names and encoding.

        my @hdr = $csv->header ($fh);
        $csv->header ($fh, { sep_set => [ ";", ",", "|", "\t" ] });
        $csv->header ($fh, { detect_bom => 1, munge_column_names => "lc" });

       The first argument should be a file handle.

       This method resets some object properties,  as it is supposed to be invoked only once per file or stream.
       It will leave attributes "column_names" and "bound_columns" alone of setting column  names  is  disabled.
       Reading headers on previously process objects might fail on perl-5.8.0 and older.

       Assuming  that  the  file  opened  for  parsing has a header, and the header does not contain problematic
       characters like embedded newlines,   read the first line from the open handle  then  auto-detect  whether
       the header separates the column names with a character from the allowed separator list.

       If  any  of  the allowed separators matches,  and none of the other allowed separators match,  set  "sep"
       to that  separator  for the current CSV_XS instance and use it to parse the  first  line,  map  those  to
       lowercase, and use that to set the instance "column_names":

        my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });
        open my $fh, "<", "file.csv";
        binmode $fh; # for Windows
        $csv->header ($fh);
        while (my $row = $csv->getline_hr ($fh)) {
            ...
            }

       If  the header is empty,  contains more than one unique separator out of the allowed set,  contains empty
       fields,   or contains identical fields  (after folding), it will croak with error 1010,  1011,  1012,  or
       1013 respectively.

       If  the  header contains embedded newlines or is not valid  CSV  in any other way, this method will croak
       and leave the parse error untouched.

       A successful call to "header"  will always set the  "sep"  of the $csv object. This behavior can  not  be
       disabled.

       return value

       On error this method will croak.

       In list context,  the headers will be returned whether they are used to set "column_names" or not.

       In  scalar  context,  the  instance  itself  is  returned.   Note: the values as found in the header will
       effectively be  lost if  "set_column_names" is false.

       Options

       sep_set
          $csv->header ($fh, { sep_set => [ ";", ",", "|", "\t" ] });

         The list of legal separators defaults to "[ ";", "," ]" and can be changed by this option.  As this  is
         probably the most often used option,  it can be passed on its own as an unnamed argument:

          $csv->header ($fh, [ ";", ",", "|", "\t", "::", "\x{2063}" ]);

         Multi-byte  sequences are allowed,  both multi-character and  Unicode.  See "sep".

       detect_bom
          $csv->header ($fh, { detect_bom => 1 });

         The  default  behavior is to detect if the header line starts with a BOM.  If the header has a BOM, use
         that to set the encoding of $fh.  This default behavior can be disabled by passing  a  false  value  to
         "detect_bom".

         Supported  encodings  from  BOM  are:  UTF-8,  UTF-16BE,  UTF-16LE, UTF-32BE,  and UTF-32LE. BOM's also
         support UTF-1, UTF-EBCDIC, SCSU, BOCU-1,  and  GB-18030  but  Encode  does  not  (yet).  UTF-7  is  not
         supported.

         The encoding is set using "binmode" on $fh.

         If  the  handle  was  opened  in a (correct) encoding,  this method will  not alter the encoding, as it
         checks the leading bytes of the first line.

       munge_column_names
         This option offers the means to modify the column names into something  that  is  most  useful  to  the
         application.   The default is to map all column names to lower case.

          $csv->header ($fh, { munge_column_names => "lc" });

         The following values are available:

           lc     - lower case
           uc     - upper case
           none   - do not change
           \%hash - supply a mapping
           \&cb   - supply a callback

         Literal:

          $csv->header ($fh, { munge_column_names => "none" });

         Hash:

          $csv->header ($fh, { munge_column_names => { foo => "sombrero" });

         if a value does not exist, the original value is used unchanged

         Callback:

          $csv->header ($fh, { munge_column_names => sub { fc } });
          $csv->header ($fh, { munge_column_names => sub { "column_".$col++ } });
          $csv->header ($fh, { munge_column_names => sub { lc (s/\W+/_/gr) } });

         As this callback is called in a "map", you can use $_ directly.

       set_column_names
          $csv->header ($fh, { set_column_names => 1 });

         The default is to set the instances column names using  "column_names" if the method is successful,  so
         subsequent calls to "getline_hr" can return a hash. Disable setting the header can be forced by using a
         false value for this option.

         As described in "return value" above, content is lost in scalar context.

       Validation

       When  receiving  CSV  files from external sources,  this method can be used to protect against changes in
       the layout by restricting to known headers  (and typos in the header fields).

        my %known = (
            "record key" => "c_rec",
            "rec id"     => "c_rec",
            "id_rec"     => "c_rec",
            "kode"       => "code",
            "code"       => "code",
            "vaule"      => "value",
            "value"      => "value",
            );
        my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });
        open my $fh, "<", $source or die "$source: $!";
        $csv->header ($fh, { munge_column_names => sub {
            s/\s+$//;
            s/^\s+//;
            $known{lc $_} or die "Unknown column '$_' in $source";
            }});
        while (my $row = $csv->getline_hr ($fh)) {
            say join "\t", $row->{c_rec}, $row->{code}, $row->{value};
            }

   bind_columns
       Takes a list of scalar references to be used for output with  "print"  or to store in the fields  fetched
       by "getline".  When you do not pass enough references to store the fetched fields in, "getline" will fail
       with  error  3006.   If  you  pass  more  than  there are fields to return,  the content of the remaining
       references is left untouched.

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

       To reset or clear all column binding, call "bind_columns" with the 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 of current bindings or "undef" if
       no binds are active.

       Note that in parsing with  "bind_columns",  the fields are set on the fly.   That  implies  that  if  the
       third  field of a row causes an error  (or this row has just two fields where the previous row had more),
       the first two fields already have been assigned the values of the current row,  while  the  rest  of  the
       fields  will  still  hold the values of the previous row.  If you want the parser to fail in these cases,
       use the "strict" attribute.

   eof
        $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.

       Note that if the parsing of the last line caused an error,  "eof" is still true.  That means that if  you
       are not using "auto_diag", an idiom like

        while (my $row = $csv->getline ($fh)) {
            # ...
            }
        $csv->eof or $csv->error_diag;

       will not report the error. You would have to change that to

        while (my $row = $csv->getline ($fh)) {
            # ...
            }
        +$csv->error_diag and $csv->error_diag;

   types
        $csv->types (\@tref);

       This  method  is  used  to  force  that  (all)  columns are of a given type.  For example, if you have an
       integer column,  two  columns  with  doubles  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 while  parsing,   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 method 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".

   meta_info
        @flags = $csv->meta_info ();

       This method 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  inform  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.

   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 fields where content ",20070108," is to be treated as a numeric value,  and  where
       ","20070108"," is explicitly marked as character string data.

       This method is only valid when "keep_meta_info" is set to a true value.

   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]".

       This method is only valid when "keep_meta_info" is set to a true value.

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

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

        $csv->keep_meta_info (1);
        while (my $hr = $csv->getline_hr ($fh)) {
            $csv->is_missing (0) and next; # This was an empty line
            }

       When using  "getline_hr",  it is impossible to tell if the  parsed 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.

       If   "keep_meta_info"   is  "false",  "is_missing"  will always return "undef", regardless of $column_idx
       being valid or not. If this attribute is "true" it will return either 0 (the field is present) or 1  (the
       field is missing).

       A special case is the empty line.  If the line is completely empty -  after dealing with the flags - this
       is  still  a valid CSV line:  it is a record of just one single empty field. However, if "keep_meta_info"
       is set, invoking "is_missing" with index 0 will now return true.

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

       This method returns the status of the last invoked "combine" or "parse" call. Status is success (true: 1)
       or failure (false: "undef" or 0).

   error_input
        $bad_argument = $csv->error_input ();

       This method returns the erroneous argument (if it exists) of "combine" or "parse",  whichever was  called
       more recently.  If the last invocation was successful, "error_input" will return "undef".

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

       If (and only if) an error occurred,  this function returns  the diagnostics of that error.

       If  called  in void context,  this will print the internal error code and the associated error message to
       STDERR.

       If called in list context,  this will return  the error code  and the error message in  that  order.   If
       the last error was from parsing, the rest of the values returned are a best guess at the location  within
       the  line   that was being parsed. Their values are 1-based.  The position currently is index of the byte
       at which the parsing failed in the current record. It might  change  to  be  the  index  of  the  current
       character  in  a  later  release.  The records is the index of the record parsed by the csv instance. The
       field number is the index of the field  the  parser  thinks  it  is  currently   trying  to   parse.  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 context.

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

   record_number
        $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.

   SetDiag
        $csv->SetDiag (0);

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

FUNCTIONS

   csv
       This function is not exported by default and should be explicitly requested:

        use Text::CSV_XS qw( csv );

       This is an high-level function that aims at simple (user) interfaces.  This can be used to  read/parse  a
       "CSV"  file or stream (the default behavior) or to produce a file or write to a stream (define the  "out"
       attribute).  It returns an array- or hash-reference on parsing (or "undef" on fail) or the numeric  value
       of   "error_diag"  on writing.  When this function fails you can get to the error using the class call to
       "error_diag"

        my $aoa = csv (in => "test.csv") or
            die Text::CSV_XS->error_diag;

       This function takes the arguments as key-value pairs. This can be passed as a list  or  as  an  anonymous
       hash:

        my $aoa = csv (  in => "test.csv", sep_char => ";");
        my $aoh = csv ({ in => $fh, headers => "auto" });

       The  arguments passed consist of two parts:  the arguments to "csv" itself and the optional attributes to
       the  "CSV"  object used inside the function as enumerated and explained in "new".

       If not overridden, the default option used for CSV is

        auto_diag   => 1
        escape_null => 0

       The option that is always set and cannot be altered is

        binary      => 1

       As this function will likely be used in one-liners,  it allows  "quote" to be abbreviated as "quo",   and
       "escape_char" to be abbreviated as  "esc" or "escape".

       Alternative invocations:

        my $aoa = Text::CSV_XS::csv (in => "file.csv");

        my $csv = Text::CSV_XS->new ();
        my $aoa = $csv->csv (in => "file.csv");

       In  the  latter case, the object attributes are used from the existing object and the attribute arguments
       in the function call are ignored:

        my $csv = Text::CSV_XS->new ({ sep_char => ";" });
        my $aoh = $csv->csv (in => "file.csv", bom => 1);

       will parse using ";" as "sep_char", not ",".

       in

       Used to specify the source.  "in" can be a file name (e.g. "file.csv"), which will be  opened for reading
       and closed when finished,  a file handle (e.g.  $fh or "FH"),  a reference to  a  glob  (e.g.  "\*ARGV"),
       the glob itself (e.g. *STDIN), or a reference to a scalar (e.g. "\q{1,2,"csv"}").

       When  used  with  "out",  "in"  should be a reference to a CSV structure (AoA or AoH)  or a CODE-ref that
       returns an array-reference or a hash-reference.  The code-ref will be invoked with no arguments.

        my $aoa = csv (in => "file.csv");

        open my $fh, "<", "file.csv";
        my $aoa = csv (in => $fh);

        my $csv = [ [qw( Foo Bar )], [ 1, 2 ], [ 2, 3 ]];
        my $err = csv (in => $csv, out => "file.csv");

       If called in void context without the "out" attribute, the resulting ref will  be  used  as  input  to  a
       subsequent call to csv:

        csv (in => "file.csv", filter => { 2 => sub { length > 2 }})

       will be a shortcut to

        csv (in => csv (in => "file.csv", filter => { 2 => sub { length > 2 }}))

       where, in the absence of the "out" attribute, this is a shortcut to

        csv (in  => csv (in => "file.csv", filter => { 2 => sub { length > 2 }}),
             out => *STDOUT)

       out

        csv (in => $aoa, out => "file.csv");
        csv (in => $aoa, out => $fh);
        csv (in => $aoa, out =>   STDOUT);
        csv (in => $aoa, out =>  *STDOUT);
        csv (in => $aoa, out => \*STDOUT);
        csv (in => $aoa, out => \my $data);

       In output mode, the default CSV options when producing CSV are

        eol       => "\r\n"

       The "fragment" attribute is ignored in output mode.

       "out" can be a file name  (e.g.  "file.csv"),  which will be opened for writing and closed when finished,
       a  file  handle  (e.g.  $fh  or  "FH"),   a reference to a glob (e.g. "\*STDOUT"),  the glob itself (e.g.
       *STDOUT), or a reference to a scalar (e.g. "\my $data").

        csv (in => sub { $sth->fetch },            out => "dump.csv");
        csv (in => sub { $sth->fetchrow_hashref }, out => "dump.csv",
             headers => $sth->{NAME_lc});

       When a code-ref is used for "in", the output is generated  per invocation, so no buffering  is  involved.
       This implies that there is no size restriction on the number of records. The "csv" function ends when the
       coderef returns a false value.

       encoding

       If passed,  it should be an encoding accepted by the  ":encoding()" option to "open". There is no default
       value.  This  attribute  does not work in perl 5.6.x.  "encoding" can be abbreviated to "enc" for ease of
       use in command line invocations.

       If "encoding" is set to the literal value "auto", the method "header"  will  be  invoked  on  the  opened
       stream  to  check  if  there is a BOM and set the encoding accordingly.   This is equal to passing a true
       value in the option "detect_bom".

       detect_bom

       If  "detect_bom"  is given, the method  "header"  will be invoked on the opened stream to check if  there
       is a BOM and set the encoding accordingly.

       "detect_bom" can be abbreviated to "bom".

       This is the same as setting "encoding" to "auto".

       Note that as the method  "header" is invoked,  its default is to also set the headers.

       headers

       If this attribute is not given, the default behavior is to produce an array of arrays.

       If  "headers"  is  supplied,   it  should  be  an anonymous list of column names, an anonymous hashref, a
       coderef, or a literal flag:  "auto", "lc", "uc", or "skip".

       skip
         When "skip" is used, the header will not be included in the output.

          my $aoa = csv (in => $fh, headers => "skip");

       auto
         If "auto" is used, the first line of the "CSV" source will be read as the list  of  field  headers  and
         used to produce an array of hashes.

          my $aoh = csv (in => $fh, headers => "auto");

       lc
         If  "lc" is used,  the first line of the  "CSV" source will be read as the list of field headers mapped
         to  lower case and used to produce an array of hashes. This is a variation of "auto".

          my $aoh = csv (in => $fh, headers => "lc");

       uc
         If "uc" is used,  the first line of the  "CSV" source will be read as the list of field headers  mapped
         to  upper case and used to produce an array of hashes. This is a variation of "auto".

          my $aoh = csv (in => $fh, headers => "uc");

       CODE
         If  a  coderef  is used,  the first line of the  "CSV" source will be read as the list of mangled field
         headers in which each field is passed as the only argument to the coderef. This list is used to produce
         an array of hashes.

          my $aoh = csv (in      => $fh,
                         headers => sub { lc ($_[0]) =~ s/kode/code/gr });

         this example is a variation of using "lc" where all occurrences of "kode" are replaced with "code".

       ARRAY
         If  "headers"  is an anonymous list,  the entries in the list will be used as field  names.  The  first
         line is considered data instead of headers.

          my $aoh = csv (in => $fh, headers => [qw( Foo Bar )]);
          csv (in => $aoa, out => $fh, headers => [qw( code description price )]);

       HASH
         If  "headers" is an hash reference, this implies "auto", but header fields for that exist as key in the
         hashref will be replaced by the value for that key. Given a CSV file like

          post-kode,city,name,id number,fubble
          1234AA,Duckstad,Donald,13,"X313DF"

         using

          csv (headers => { "post-kode" => "pc", "id number" => "ID" }, ...

         will return an entry like

          { pc     => "1234AA",
            city   => "Duckstad",
            name   => "Donald",
            ID     => "13",
            fubble => "X313DF",
            }

       See also "munge_column_names" and "set_column_names".

       munge_column_names

       If "munge_column_names" is set,  the method  "header"  is invoked on the opened stream with all  matching
       arguments to detect and set the headers.

       "munge_column_names" can be abbreviated to "munge".

       key

       If passed,  will default  "headers"  to "auto" and return a hashref instead of an array of hashes.

        my $ref = csv (in => "test.csv", key => "code");

       with test.csv like

        code,product,price,color
        1,pc,850,gray
        2,keyboard,12,white
        3,mouse,5,black

       will return

         { 1   => {
               code    => 1,
               color   => 'gray',
               price   => 850,
               product => 'pc'
               },
           2   => {
               code    => 2,
               color   => 'white',
               price   => 12,
               product => 'keyboard'
               },
           3   => {
               code    => 3,
               color   => 'black',
               price   => 5,
               product => 'mouse'
               }
           }

       The "key" attribute can be combined with "headers" for "CSV" date that has no header line, like

        my $ref = csv (
            in      => "foo.csv",
            headers => [qw( c_foo foo bar description stock )],
            key     =>     "c_foo",
            );

       keep_headers

       When  using  hashes,  keep the column names into the arrayref passed,  so all headers are available after
       the call in the original order.

        my $aoh = csv (in => "file.csv", keep_headers => \my @hdr);

       This attribute can be abbreviated to "kh" or passed as "keep_column_names".

       This attribute implies a default of "auto" for the "headers" attribute.

       fragment

       Only output the fragment as defined in the "fragment" method. This  option  is  ignored  when  generating
       "CSV". See "out".

       Combining all of them could give something like

        use Text::CSV_XS qw( csv );
        my $aoh = csv (
            in       => "test.txt",
            encoding => "utf-8",
            headers  => "auto",
            sep_char => "|",
            fragment => "row=3;6-9;15-*",
            );
        say $aoh->[15]{Foo};

       sep_set

       If  "sep_set"  is  set,  the method "header" is invoked on the opened stream to detect and set "sep_char"
       with the given set.

       "sep_set" can be abbreviated to "seps".

       Note that as the  "header" method is invoked,  its default is to also set the headers.

       set_column_names

       If  "set_column_names" is passed,  the method "header" is invoked on the opened stream with all arguments
       meant for "header".

       If "set_column_names" is passed as a false value, the content of the first row is only preserved  if  the
       output is AoA:

       With an input-file like

        bAr,foo
        1,2
        3,4,5

       This call

        my $aoa = csv (in => $file, set_column_names => 0);

       will result in

        [[ "bar", "foo"     ],
         [ "1",   "2"       ],
         [ "3",   "4",  "5" ]]

       and

        my $aoa = csv (in => $file, set_column_names => 0, munge => "none");

       will result in

        [[ "bAr", "foo"     ],
         [ "1",   "2"       ],
         [ "3",   "4",  "5" ]]

   Callbacks
       Callbacks enable actions triggered from the inside of Text::CSV_XS.

       While  most  of what this enables  can easily be done in an  unrolled loop as described in the "SYNOPSIS"
       callbacks can be used to meet special demands or enhance the "csv" function.

       error
          $csv->callbacks (error => sub { $csv->SetDiag (0) });

         the "error"  callback is invoked when an error occurs,  but  only  when "auto_diag" is set  to  a  true
         value. A callback is invoked with the values returned by "error_diag":

          my ($c, $s);

          sub ignore3006
          {
              my ($err, $msg, $pos, $recno, $fldno) = @_;
              if ($err == 3006) {
                  # ignore this error
                  ($c, $s) = (undef, undef);
                  Text::CSV_XS->SetDiag (0);
                  }
              # Any other error
              return;
              } # ignore3006

          $csv->callbacks (error => \&ignore3006);
          $csv->bind_columns (\$c, \$s);
          while ($csv->getline ($fh)) {
              # Error 3006 will not stop the loop
              }

       after_parse
          $csv->callbacks (after_parse => sub { push @{$_[1]}, "NEW" });
          while (my $row = $csv->getline ($fh)) {
              $row->[-1] eq "NEW";
              }

         This  callback  is  invoked after parsing with  "getline"  only if no  error occurred.  The callback is
         invoked with two arguments:   the current "CSV" parser object and an  array  reference  to  the  fields
         parsed.

         The  return  code  of  the callback is ignored  unless it is a reference to the string "skip", in which
         case the record will be skipped in "getline_all".

          sub add_from_db
          {
              my ($csv, $row) = @_;
              $sth->execute ($row->[4]);
              push @$row, $sth->fetchrow_array;
              } # add_from_db

          my $aoa = csv (in => "file.csv", callbacks => {
              after_parse => \&add_from_db });

         This hook can be used for validation:

         FAIL
           Die if any of the records does not validate a rule:

            after_parse => sub {
                $_[1][4] =~ m/^[0-9]{4}\s?[A-Z]{2}$/ or
                    die "5th field does not have a valid Dutch zipcode";
                }

         DEFAULT
           Replace invalid fields with a default value:

            after_parse => sub { $_[1][2] =~ m/^\d+$/ or $_[1][2] = 0 }

         SKIP
           Skip records that have invalid fields (only applies to "getline_all"):

            after_parse => sub { $_[1][0] =~ m/^\d+$/ or return \"skip"; }

       before_print
          my $idx = 1;
          $csv->callbacks (before_print => sub { $_[1][0] = $idx++ });
          $csv->print (*STDOUT, [ 0, $_ ]) for @members;

         This callback is invoked  before printing with  "print"  only if no error occurred.   The  callback  is
         invoked  with  two  arguments:   the  current  "CSV" parser object and an array reference to the fields
         passed.

         The return code of the callback is ignored.

          sub max_4_fields
          {
              my ($csv, $row) = @_;
              @$row > 4 and splice @$row, 4;
              } # max_4_fields

          csv (in => csv (in => "file.csv"), out => *STDOUT,
              callbacks => { before print => \&max_4_fields });

         This callback is not active for "combine".

       Callbacks for csv ()

       The "csv" allows for some callbacks that do not integrate in XS internals  but  only  feature  the  "csv"
       function.

         csv (in        => "file.csv",
              callbacks => {
                  filter       => { 6 => sub { $_ > 15 } },    # first
                  after_parse  => sub { say "AFTER PARSE";  }, # first
                  after_in     => sub { say "AFTER IN";     }, # second
                  on_in        => sub { say "ON IN";        }, # third
                  },
              );

         csv (in        => $aoh,
              out       => "file.csv",
              callbacks => {
                  on_in        => sub { say "ON IN";        }, # first
                  before_out   => sub { say "BEFORE OUT";   }, # second
                  before_print => sub { say "BEFORE PRINT"; }, # third
                  },
              );

       filter
         This  callback  can  be used to filter records.  It is called just after a new record has been scanned.
         The callback accepts a hashref where the keys are the index to the row (the field number, 1-based)  and
         the values are subs to return a true or false value.

          csv (in => "file.csv", filter => {
                     3 => sub { m/a/ },       # third field should contain an "a"
                     5 => sub { length > 4 }, # length of the 5th field minimal 5
                     });

          csv (in => "file.csv", filter => "not_blank");
          csv (in => "file.csv", filter => "not_empty");
          csv (in => "file.csv", filter => "filled");

         If  the  keys  to the filter hash contain any character that is not a digit it will also implicitly set
         "headers" to "auto"  unless  "headers"  was already passed  as  argument.   When  headers  are  active,
         returning an array of hashes, the filter is not applicable to the header itself.

          csv (in => "file.csv", filter => { foo => sub { $_ > 4 }});

         All sub results should match, as in AND.

         The  context of the callback sets  $_ localized to the field indicated by the filter. The two arguments
         are as with all other callbacks, so the other fields in the current row can be seen:

          filter => { 3 => sub { $_ > 100 ? $_[1][1] =~ m/A/ : $_[1][6] =~ m/B/ }}

         If the context is set to return a list of hashes  ("headers" is defined), the current record will  also
         be available in the localized %_:

          filter => { 3 => sub { $_ > 100 && $_{foo} =~ m/A/ && $_{bar} < 1000  }}

         If  the  filter  is  used  to alter the content by changing $_,  make sure that the sub returns true in
         order not to have that record skipped:

          filter => { 2 => sub { $_ = uc }}

         will upper-case the second field, and then skip it if the resulting  content  evaluates  to  false.  To
         always accept, end with truth:

          filter => { 2 => sub { $_ = uc; 1 }}

         Predefined filters

         Given a file like (line numbers prefixed for doc purpose only):

          1:1,2,3
          2:
          3:,
          4:""
          5:,,
          6:, ,
          7:"",
          8:" "
          9:4,5,6

         not_blank
           Filter out the blank lines

           This filter is a shortcut for

            filter => { 0 => sub { @{$_[1]} > 1 or
                        defined $_[1][0] && $_[1][0] ne "" } }

           Due  to  the implementation,  it is currently impossible to also filter lines that consists only of a
           quoted empty field. These lines are also considered blank lines.

           With the given example, lines 2 and 4 will be skipped.

         not_empty
           Filter out lines where all the fields are empty.

           This filter is a shortcut for

            filter => { 0 => sub { grep { defined && $_ ne "" } @{$_[1]} } }

           A space is not regarded being empty, so given the example data, lines 2, 3, 4, 5, and 7 are skipped.

         filled
           Filter out lines that have no visible data

           This filter is a shortcut for

            filter => { 0 => sub { grep { defined && m/\S/ } @{$_[1]} } }

           This filter rejects all lines that not have at least one field that does not evaluate  to  the  empty
           string.

           With the given example data, this filter would skip lines 2 through 8.

       after_in
         This  callback  is  invoked for each record after all records have been parsed but before returning the
         reference to the caller.  The hook is invoked with two arguments:  the current   "CSV"   parser  object
         and  a   reference  to  the record.   The reference can be a reference to a  HASH  or a reference to an
         ARRAY as determined by the arguments.

         This callback can also be passed as  an attribute without the  "callbacks" wrapper.

       before_out
         This callback is invoked for each record before the record is printed.  The hook is  invoked  with  two
         arguments:   the  current  "CSV"  parser object and a reference to the record.   The reference can be a
         reference to a  HASH or a reference to an ARRAY as determined by the arguments.

         This callback can also be passed as an attribute  without the  "callbacks" wrapper.

         This callback makes the row available in %_ if the row is a hashref.  In this case %_ is  writable  and
         will change the original row.

       on_in
         This callback acts exactly as the "after_in" or the "before_out" hooks.

         This callback can also be passed as an attribute  without the  "callbacks" wrapper.

         This  callback  makes the row available in %_ if the row is a hashref.  In this case %_ is writable and
         will change the original row. So e.g. with

           my $aoh = csv (
               in      => \"foo\n1\n2\n",
               headers => "auto",
               on_in   => sub { $_{bar} = 2; },
               );

         $aoh will be:

           [ { foo => 1,
               bar => 2,
               }
             { foo => 2,
               bar => 2,
               }
             ]

       csv
         The function  "csv" can also be called as a method or with an existing Text::CSV_XS object. This  could
         help if the function is to be invoked a lot of times and the overhead of creating the object internally
         over  and  over again would be prevented by passing an existing instance.

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

          my $aoa = $csv->csv (in => $fh);
          my $aoa = csv (in => $fh, csv => $csv);

         both act the same. Running this 20000 times on a 20 lines CSV file,  showed a 53% speedup.

INTERNALS

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

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

EXAMPLES

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

       or

        my $aoa = csv (in => "file.csv", on_in => sub {
            # do something with %_
            });

       Reading only a single column

        my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });
        open my $fh, "<", "file.csv" or die "file.csv: $!";
        # get only the 4th column
        my @column = map { $_->[3] } @{$csv->getline_all ($fh)};
        close $fh or die "file.csv: $!";

       with "csv", you could do

        my @column = map { $_->[0] }
            @{csv (in => "file.csv", fragment => "col=4")};

   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 ();
            }

       Parsing CSV from memory

       Given a complete CSV data-set in scalar $data,  generate a list of lists to represent the rows and fields

        # The data
        my $data = join "\r\n" => map { join "," => 0 .. 5 } 0 .. 5;

        # in a loop
        my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });
        open my $fh, "<", \$data;
        my @foo;
        while (my $row = $csv->getline ($fh)) {
            push @foo, $row;
            }
        close $fh;

        # a single call
        my $foo = csv (in => \$data);

   Printing CSV data
       The fast way: using "print"

       An example for creating "CSV" files using the "print" method:

        my $csv = Text::CSV_XS->new ({ binary => 1, eol => $/ });
        open my $fh, ">", "foo.csv" or die "foo.csv: $!";
        for (1 .. 10) {
            $csv->print ($fh, [ $_, "$_" ]) 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: $!";

       Generating CSV into memory

       Format a data-set (@foo) into a scalar value in memory ($data):

        # The data
        my @foo = map { [ 0 .. 5 ] } 0 .. 3;

        # in a loop
        my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1, eol => "\r\n" });
        open my $fh, ">", \my $data;
        $csv->print ($fh, $_) for @foo;
        close $fh;

        # a single call
        csv (in => \@foo, out => \my $data);

   Rewriting CSV
       Rewrite "CSV" files with ";" as separator character to well-formed "CSV":

        use Text::CSV_XS qw( csv );
        csv (in => csv (in => "bad.csv", sep_char => ";"), out => *STDOUT);

       As "STDOUT" is now default in "csv", a one-liner converting a UTF-16 CSV file with BOM and TAB-separation
       to valid UTF-8 CSV could be:

        $ perl -C3 -MText::CSV_XS=csv -we\
           'csv(in=>"utf16tab.csv",encoding=>"utf16",sep=>"\t")' >utf8.csv

   Dumping database tables to CSV
       Dumping a database table can be simple as this (TIMTOWTDI):

        my $dbh = DBI->connect (...);
        my $sql = "select * from foo";

        # using your own loop
        open my $fh, ">", "foo.csv" or die "foo.csv: $!\n";
        my $csv = Text::CSV_XS->new ({ binary => 1, eol => "\r\n" });
        my $sth = $dbh->prepare ($sql); $sth->execute;
        $csv->print ($fh, $sth->{NAME_lc});
        while (my $row = $sth->fetch) {
            $csv->print ($fh, $row);
            }

        # using the csv function, all in memory
        csv (out => "foo.csv", in => $dbh->selectall_arrayref ($sql));

        # using the csv function, streaming with callbacks
        my $sth = $dbh->prepare ($sql); $sth->execute;
        csv (out => "foo.csv", in => sub { $sth->fetch            });
        csv (out => "foo.csv", in => sub { $sth->fetchrow_hashref });

       Note that this does not discriminate between "empty" values and NULL-values from the database,   as  both
       will be the same empty field in CSV.  To enable distinction between the two, use "quote_empty".

        csv (out => "foo.csv", in => sub { $sth->fetch }, quote_empty => 1);

       If  the  database  import  utility  supports special sequences to insert "NULL" values into the database,
       like MySQL/MariaDB supports "\N",  use a filter or a map

        csv (out => "foo.csv", in => sub { $sth->fetch },
                            on_in => sub { $_ //= "\\N" for @{$_[1]} });

        while (my $row = $sth->fetch) {
            $csv->print ($fh, [ map { $_ // "\\N" } @$row ]);
            }

       these special sequences are not recognized by  Text::CSV_XS  on parsing the CSV generated like this,  but
       map and filter are your friends again

        while (my $row = $csv->getline ($fh)) {
            $sth->execute (map { $_ eq "\\N" ? undef : $_ } @$row);
            }

        csv (in => "foo.csv", filter => { 1 => sub {
            $sth->execute (map { $_ eq "\\N" ? undef : $_ } @{$_[1]}); 0; }});

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

        1. https://github.com/Tux/Text-CSV_XS/tree/master/examples
        2. https://github.com/Tux/Text-CSV_XS

       The following files can be found there:

       parser-xs.pl
         This can be used as  a  boilerplate  to  parse  invalid  "CSV"   and  parse  beyond  (expected)  errors
         alternative to using the "error" callback.

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

       csv-check
         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 files/utf8.csv  with csv-check 1.9
          using Text::CSV_XS 1.32 with perl 5.26.0 and Unicode 9.0.0
          OK: rows: 1, columns: 2
              sep = <,>, quo = <">, bin = <1>, eol = <"\n">

       csv2xls
         A script to convert "CSV" to Microsoft Excel  ("XLS").  This  requires  extra  modules  Date::Calc  and
         Spreadsheet::WriteExcel.  The  converter  accepts various options and can produce UTF-8 compliant Excel
         files.

       csv2xlsx
         A script to convert "CSV" to Microsoft Excel  ("XLSX").   This  requires  the  modules  Date::Calc  and
         Spreadsheet::Writer::XLSX.   The  converter does accept various options including merging several "CSV"
         files into a single Excel file.

       csvdiff
         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

       rewrite.pl
         A  script  to rewrite (in)valid CSV into valid CSV files.  Script has options to generate confusing CSV
         files or CSV files that conform to Dutch MS-Excel exports (using ";" as separation).

         Script - by default - honors BOM  and auto-detects separation converting it  to  default  standard  CSV
         with "," as separator.

CAVEATS

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

       As of version 1.17, a lone first line with just

         sep=;

       will be recognized and honored when parsing with "getline".

TODO

       More Errors & Warnings
         New extensions ought to be  clear and concise  in reporting what  error has occurred where and why, and
         maybe also offer a remedy to the problem.

         "error_diag" is a (very) good start, but there is more work to be done in this area.

         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);

         Metadata Vocabulary for Tabular Data <http://w3c.github.io/csvw/metadata/> (a W3C editor's draft) could
         be an example for supporting more metadata.

       Parse the whole file at once
         Implement new methods or functions  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  the "csv" function already supports most of this,  but does not return flags. "getline_all"
         returns all rows for an open stream, but this will not return flags either.  "fragment"  can reduce the
         required  rows or columns, but cannot combine them.

       Cookbook
         Write a document that has recipes for  most known   non-standard   (and  maybe  some  standard)   "CSV"
         formats,  including formats that use  "TAB",  ";", "|", or other non-comma separators.

         Examples   could   be   taken   from   W3C's   CSV   on   the   Web:   Use   Cases   and   Requirements
         <http://w3c.github.io/csvw/use-cases-and-requirements/index.html>

       Steal
         Steal   good   new   ideas   and   features   from   PapaParse   <http://papaparse.com>    or    csvkit
         <http://csvkit.readthedocs.org>.

       Perl6 support
         I'm  already  working on perl6 support here <https://github.com/Tux/CSV>. No promises yet on when it is
         finished (or fast). Trying to keep the API alike as much as possible.

   NOT TODO
       combined methods
         Requests for adding means (methods) that combine "combine" and "string" in a single call  will  not  be
         honored  (use "print" instead).   Likewise for "parse" and "fields"  (use "getline" instead), given the
         problems with embedded newlines.

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

       • DIAGNOSTICS section in pod to *describe* the errors (see below)

EBCDIC

       The current hard-coding of characters and character ranges  makes this code unusable on "EBCDIC" systems.
       Recent work in perl-5.20 might change that.

       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 "...";

DIAGNOSTICS

       Still under construction ...

       If  an error occurs,  "$csv->error_diag" can be used to get 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".

       The "$csv->error_diag" method is automatically invoked 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.

       Errors can be (individually) caught using the "error" callback.

       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:

       • INI

         Initialization error or option conflict.

       • ECR

         Carriage-Return related parse error.

       • EOF

         End-Of-File related parse error.

       • EIQ

         Parse error inside quotation.

       • EIF

         Parse error inside field.

       • ECB

         Combine error.

       • EHR

         HashRef parse related error.

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

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

         The  separation character  cannot be equal to  the quotation character or to the escape character,   as
         this would invalidate all parsing rules.

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

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

       • 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.

       • 1004 "INI - callbacks should be undef or a hashref"

         The "callbacks"  attribute only allows one to be "undef" or a hash reference.

       • 1005 "INI - EOL too long"

         The value passed for EOL is exceeding its maximum length (16).

       • 1006 "INI - SEP too long"

         The value passed for SEP is exceeding its maximum length (16).

       • 1007 "INI - QUOTE too long"

         The value passed for QUOTE is exceeding its maximum length (16).

       • 1008 "INI - SEP undefined"

         The value passed for SEP should be defined and not empty.

       • 1010 "INI - the header is empty"

         The header line parsed in the "header" is empty.

       • 1011 "INI - the header contains more than one valid separator"

         The  header  line  parsed in the  "header"  contains more than one  (unique) separator character out of
         the allowed set of separators.

       • 1012 "INI - the header contains an empty field"

         The header line parsed in the "header" is contains an empty field.

       • 1013 "INI - the header contains nun-unique fields"

         The header line parsed in the  "header"  contains at least  two identical fields.

       • 1014 "INI - header called on undefined stream"

         The header line cannot be parsed from an undefined sources.

       • 1500 "PRM - Invalid/unsupported argument(s)"

         Function or method called with invalid argument(s) or parameter(s).

       • 1501 "PRM - The key attribute is passed as an unsupported type"

         The "key" attribute is of an unsupported type.

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

         When  "eol"  has  been  set  to  anything  but 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.

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

         Sequences like "1,foo,"bar"baz,22,1" are not allowed. "bar" is a quoted field  and  after  the  closing
         double-quote, there should be either a new-line sequence or a separation character.

       • 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".

       • 2013 "INI - Specification error for fragments RFC7111"

         Invalid specification for URI "fragment" specification.

       • 2014 "ENF - Inconsistent number of fields"

         Inconsistent number of fields under strict parsing.

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

         Sequences like "1,"foo\nbar",22,1" are allowed only when the binary option has been selected  with  the
         constructor.

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

         Sequences  like  "1,"foo\rbar",22,1" are allowed only when the binary option has been selected with the
         constructor.

       • 2023 "EIQ - QUO character not allowed"

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

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

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

       • 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 attribute "allow_loose_escape".

       • 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 if the content is valid UTF-8. Set "binary" to 1 to accept binary data.

       • 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.

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

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

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

       • 2034 "EIF - Loose unescaped quote"

       • 2035 "EIF - Escaped EOF in unquoted field"

       • 2036 "EIF - ESC error"

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

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

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

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

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

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

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

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

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

       • 3008 "EHR - unexpected error in bound fields"

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

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

SEE ALSO

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

       If  you  are using perl6,  you can have a look at  "Text::CSV"  in the perl6 ecosystem, offering the same
       features.

       non-perl

       A CSV parser in JavaScript,  also used by W3C  <http://www.w3.org>,   is  the  multi-threaded  in-browser
       PapaParse <http://papaparse.com/>.

       csvkit <http://csvkit.readthedocs.org> is a python CSV parsing toolkit.

AUTHOR

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

       Jochen Wiedmann <joe@ispsoft.de> rewrote the en- and decoding in C by implementing a simple  finite-state
       machine.    He  added  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 most RT bugs,  added all the allow
       flags and the "csv" function. See ChangeLog releases 0.25 and on.

COPYRIGHT AND LICENSE

        Copyright (C) 2007-2017 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 and/or modify  it  under  the  same  terms  as  Perl
       itself.

perl v5.26.1                                       2017-11-11                                        CSV_XS(3pm)