tag3

Usage

Overview

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

Commands

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.

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.

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

==

String equals

!=

String not equal

<=

Less than or equal

-in

Is the test value a member of the list given as the matchvalue

-contains

Does the match value contain the test value as a case insensitive substring.

-earlier

Date earlier

-later

Date later - dates are in ISO format (yyyy-mm-dd [hh:mm:ss]).

-exists

Does the label exist in this record.