NAME

       tag - Manipulate tagged files

SYNOPSIS

       tag option ?arg arg ...?

DESCRIPTION

       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.

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

AUTHOR

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

                                           July 3, 2000                                 tag(3tcl)