8.5.6 presetting/configuring columns

Any option that is not marked as not presettable may be preset by loading values from configuration ("rc" or "ini") files, and values from environment variables named COLUMNS and COLUMNS_<OPTION_NAME>. <OPTION_NAME> must be one of the options listed above in upper case and segmented with underscores. The COLUMNS variable will be tokenized and parsed like the command line. The remaining variables are tested for existence and their values are treated like option arguments.

libopts will search in 2 places for configuration files:

• $PWD
• $HOME

The environment variables PWD, and HOME are expanded and replaced when ‘columns’ runs. For any of these that are plain files, they are simply processed. For any that are directories, then a file named ‘.columnsrc’ is searched for within that directory and processed.

Configuration files may be in a wide variety of formats. The basic format is an option name followed by a value (argument) on the same line. Values may be separated from the option name with a colon, equal sign or simply white space. Values may be continued across multiple lines by escaping the newline with a backslash.

Multiple programs may also share the same initialization file. Common options are collected at the top, followed by program specific segments. The segments are separated by lines like:

[COLUMNS]

or by

<?program columns>

Do not mix these styles within one configuration file.

Compound values and carefully constructed string values may also be specified using XML syntax:

<option-name>
   <sub-opt>...&lt;...&gt;...</sub-opt>
</option-name>

yielding an option-name.sub-opt string value of

"...<...>..."

AutoOpts does not track suboptions. You simply note that it is a hierarchicly valued option. AutoOpts does provide a means for searching the associated name/value pair list (see: optionFindValue).

The command line options relating to configuration and/or usage help are:

version (-v)

Print the program version to standard out, optionally with licensing information, then exit 0. The optional argument specifies how much licensing detail to provide. The default is to print just the version. The licensing infomation may be selected with an option argument. Only the first letter of the argument is examined:

‘version’

Only print the version. This is the default.

‘copyright’

Name the copyright usage licensing terms.

‘verbose’

Print the full copyright usage licensing terms.

This document was generated by Bruce Korb on August 21, 2015 using texi2html 1.82.