.TH tag 3tcl "July 3, 2000
.SH NAME
tag \- Manipulate tagged files
.SH SYNOPSIS
.B tag
option ?arg arg ...?

.SH DESCRIPTION

The tag procedure provides a number of options for manipulating tagged files.

.SH COMMANDS

.TP
tag readfile filename

Reads the file with the given filename and returns a list where each list
element is a tag record, which is represented by a list of label-value pairs,
or label-value-endlabel triples.

The tag header is the first element returned.

.TP
tag writefile filename list

Takes a list in the format used internally in tcl programs for tagged data
and writes it as a tagged file.

.TP
tag extract list tests

Takes a list in tagged format, and a list of conditions, and returns a
new list in tagged format which contains those tag records which match the
conditions.

The tests is a list of test items, each of which is a list of the form
{ labelname condition matchvalue }

The conditions are
.TP
.I ==
String equals
.TP
.I !=
String not equal
.TP
.I <=
Less than or equal
.TP
.I -in
Is the test value a member of the list given as the matchvalue
.TP
.I -contains
Does the match value contain the test value as a case insensitive substring.
.TP
.I -earlier
Date earlier
.TP
.I -later
Date later - dates are in ISO format (yyyy-mm-dd [hh:mm:ss]).
.TP
.I -exists
Does the label exist in this record.


.SH BUGS

tag readfile reads the whole file into memory before turning it into a list.
Should be more memory efficient.

The -earlier and -later comparisons require TCL8.3

.SH AUTHOR
John Lines (john@paladin.demon.co.uk)