RDB: Operators: headchg

headchg

Usage: headchg [options] file.tpl

Replaces the header (first two rows) of an rdbtable with a header generated from information in the template file 'file.tpl'. Options are available to add, copy, or delete the header, or to generate a template file from an existing rdbtable.

Each line of the Template file contains info about a column, in order. The lines contain: (optional) index number (starting at 0 or 1), column name, definition, and (optional) comments or documentation, white space separated. If column name contains spaces it must be enclosed in double quotes. Names containing space characters are not recommended, however, as it is generally troublesome and error prone. A good substitute is the underscore character (_).

Lines that start with a sharp character '#' are skipped, as are blank lines. To start a column name with a sharp character '#' the name must be enclosed in double quotes. (but this is not recommended).

The number of columns in the header is normally reported on STDERR.

This operator reads an rdbtable via STDIN and writes an rdbtable via STDOUT. Options may be abbreviated. This operator uses the RDB operator: valid.

Options:

-add - Add the header to an rdbtable instead of replacing it.
-copy - Copies the header from 'file.tpl' instead of generating it. In this case 'file.tpl` is (at least a header of) an rdbtable, NOT a template file.
-del - Delete the rdbtable header instead of replacing it.
-gen - Generate header only, no rdbtable read.
-help - Print this help information.
-ndoc - Documentation in template file is NOT to be included in the second line of the header (included by default).
-quiet - No messages printed on STDERR.
-rdb - Treat 'file.tpl' as an rdbtable, use data in columns two and three to make the header.
-templ - Generate a template file from the header of the Table, on STDOUT.

As an example, to generate a template file named 'new.tpl' from the rdbtable (named sample) from the DATA section, the command would be:

        headchg  -templ  <  sample  >  new.tpl

The contents of file 'new.tpl' would then be:

        0                 NAME  6
        1                COUNT  5N
        2                  TYP  4
        3                  AMT  5N
        4                OTHER  8
        5                RIGHT  8>

To change the header of rdbtable 'sample', the procedure is to edit the file 'new.tpl', and then run 'headchg' using the modified file. For example, to change the names so that only the first letters are upper case and to make column 'OTHER' numeric, edit file 'new.tpl' so it looks like the following:

        0                 Name  6      All names are first letter upper case.
        1                Count  5N
        2                  Typ  4
        3                  Amt  5N
        4                Other  8N     Now numeric.
        5                Right  8>

Note the index in the zeroth column and the documentation in the fourth column, both of which are optional, but recommended. The command to change the header of rdbtable 'sample' and make a new rdbtable called 'new.sample' would be:

        headchg  new.tpl  <  sample  >  new.sample