csv(n)								  CSV processing							    csv(n)

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NAME

       csv - Procedures to handle CSV data.

SYNOPSIS

       package require Tcl  8.3

       package require csv  ?0.7.2?

       ::csv::iscomplete data

       ::csv::join values {sepChar ,} {delChar "}

       ::csv::joinlist values {sepChar ,} {delChar "}

       ::csv::joinmatrix matrix {sepChar ,} {delChar "}

       ::csv::read2matrix ?-alternate? chan m {sepChar ,} {expand none}

       ::csv::read2queue ?-alternate? chan q {sepChar ,}

       ::csv::report cmd matrix ?chan?

       ::csv::split ?-alternate? line {sepChar ,} {delChar "}

       ::csv::split2matrix ?-alternate? m line {sepChar ,} {expand none}

       ::csv::split2queue ?-alternate? q line {sepChar ,}

       ::csv::writematrix m chan {sepChar ,} {delChar "}

       ::csv::writequeue q chan {sepChar ,} {delChar "}

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DESCRIPTION

       The csv package provides commands to manipulate information in CSV FORMAT (CSV = Comma Separated Values).

COMMANDS

       The following commands are available:

       ::csv::iscomplete data
	      A  predicate checking if the argument data is a complete csv record. The result is a boolean flag indicating the completeness of the
	      data. The result is true if the data is complete.

       ::csv::join values {sepChar ,} {delChar "}
	      Takes a list of values and returns a string in CSV format containing these values. The separator character can  be  defined  by  the
	      caller,  but  this  is  optional.  The default is ",". The quoting character can be defined by the caller, but this is optional. The
	      default is '"'.

       ::csv::joinlist values {sepChar ,} {delChar "}
	      Takes a list of lists of values and returns a string in CSV format containing these values. The separator character can  be  defined
	      by  the  caller, but this is optional. The default is ",". The quoting character can be defined by the caller, but this is optional.
	      The default is '"'.  Each element of the outer list is considered a record, these are separated by newlines in the result. The  ele-
	      ments of each record are formatted as usual (via ::csv::join).

       ::csv::joinmatrix matrix {sepChar ,} {delChar "}
	      Takes a matrix object following the API specified for the struct::matrix package and returns a string in CSV format containing these
	      values. The separator character can be defined by the caller, but this is optional. The default is ",". The quoting character can be
	      defined  by the caller, but this is optional. The default is '"'. Each row of the matrix is considered a record, these are separated
	      by newlines in the result. The elements of each record are formatted as usual (via ::csv::join).

       ::csv::read2matrix ?-alternate? chan m {sepChar ,} {expand none}
	      A wrapper around ::csv::split2matrix (see below) reading CSV-formatted lines from the specified channel (until EOF) and adding  them
	      to the given matrix. For an explanation of the expand argument see ::csv::split2matrix.

       ::csv::read2queue ?-alternate? chan q {sepChar ,}
	      A  wrapper  around ::csv::split2queue (see below) reading CSV-formatted lines from the specified channel (until EOF) and adding them
	      to the given queue.

       ::csv::report cmd matrix ?chan?
	      A report command which can be used by the matrix methods format 2string and format 2chan. For the latter this command delegates  the
	      work  to	::csv::writematrix. cmd is expected to be either printmatrix or printmatrix2channel. The channel argument, chan, has to be
	      present for the latter and must not be present for the first.

       ::csv::split ?-alternate? line {sepChar ,} {delChar "}
	      converts a line in CSV format into a list of the values contained in the line. The character used to separate the values	from  each
	      other  can  be defined by the caller, via sepChar, but this is optional. The default is ",". The quoting character can be defined by
	      the caller, but this is optional. The default is '"'.

	      If the option -alternate is specified a slightly different syntax is used to parse the input. This syntax is explained below, in the
	      section FORMAT.

       ::csv::split2matrix ?-alternate? m line {sepChar ,} {expand none}
	      The  same as ::csv::split, but appends the resulting list as a new row to the matrix m, using the method add row. The expansion mode
	      specified via expand determines how the command handles a matrix with less columns than contained in line. The allowed modes are:

	      none   This is the default mode. In this mode it is the responsibility of the caller to ensure that the matrix has enough columns to
		     contain the full line. If there are not enough columns the list of values is silently truncated at the end to fit.

	      empty  In  this mode the command expands an empty matrix to hold all columns of the specified line, but goes no further. The overall
		     effect is that the first of a series of lines determines the number of columns in the matrix  and	all  following	lines  are
		     truncated to that size, as if mode none was set.

	      auto   In this mode the command expands the matrix as needed to hold all columns contained in line. The overall effect is that after
		     adding a series of lines the matrix will have enough columns to hold all columns of the longest line encountered so far.

       ::csv::split2queue ?-alternate? q line {sepChar ,}
	      The same as ::csv::split, but appending the resulting list as a single item to the queue q, using the method put.

       ::csv::writematrix m chan {sepChar ,} {delChar "}
	      A wrapper around ::csv::join taking all rows in the matrix m and writing them CSV formatted into the channel chan.

       ::csv::writequeue q chan {sepChar ,} {delChar "}
	      A wrapper around ::csv::join taking all items in the queue q (assumes that they are lists) and writing them CSV formatted  into  the
	      channel chan.

FORMAT

       The format of regular CSV files is specified as

       [1]    Each  record  of a csv file (comma-separated values, as exported e.g. by Excel) is a set of ASCII values separated by ",". For other
	      languages it may be ";" however, although this is not important for this case as the functions provided  here  allow  any  separator
	      character.

       [2]    If  and  only if a value contains itself the separator ",", then it (the value) has to be put between "". If the value does not con-
	      tain the separator character then quoting is optional.

       [3]    If a value contains the character ", that character is represented by "".

       [4]    The output string "" represents the value ". In other words, it is assumed that it was created through rule 3, and only  this  rule,
	      i.e. that the value was not quoted.

       An  alternate  format definition mainly used by MS products specifies that the output string "" is a representation of the empty string. In
       other words, it is assumed that the output was generated out of the empty string by quoting it (i.e. rule 2), and not through rule 3.  This
       is the only difference between the regular and the alternate format.

       The alternate format is activated through specification of the option -alternate to the various split commands.

EXAMPLE

       Using the regular format the record

       123,"123,521.2","Mary says ""Hello, I am Mary""",""

       is parsed into the items

       a) 123
       b) 123,521.2
       c) Mary says "Hello, I am Mary"
       d) (the empty string)

       Using the alternate format the result is

       a) 123
       b) 123,521.2
       c) Mary says "Hello, I am Mary"
       d) "

       instead. As can be seen only item (d) is different, now a " instead of the empty string.

BUGS, IDEAS, FEEDBACK
       This  document,	and the package it describes, will undoubtedly contain bugs and other problems.  Please report such in the category csv of
       the Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883].  Please also report any ideas for enhancements you  may  have  for
       either package and/or documentation.

SEE ALSO

       matrix, queue

KEYWORDS

       csv, matrix, package, queue, tcllib

CATEGORY

       Text processing

COPYRIGHT

       Copyright (c) 2002-2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>

csv								       0.7.2								    csv(n)