The GENESIS 3 Shell Software Component

December 28, 2015

GENESIS: Documentation

Related Documentation:

Introduction to the GENESIS Shell

After GENESIS has completed its startup procedure you should see the command prompt, genesis >, indicating that you are now in the GENESIS shell environment (G-Shell) and running an interactive GENESIS session. Note that to provide backward compatibility, the G-Shell interfaces with the Script Language Interpreter (SLI) of previous versions of GENESIS. To learn more about that functionality see here.

GENESIS Help from the Unix Command Line

Several options are recognized when starting GENESIS. They include, “--help”, “--verbose”, and “--version”. For example, typing

    $ genesis-g3 --help

returns a list of options that can be used when starting the G-Shell.

/usr/local/bin/genesis-g3 <options>  
/usr/local/bin/genesis-g3: GENESIS 3 shell.  
    --batch-mode         batch mode, means that interactive mode is disabled.  
    --execute            execute this string, may be given multiple times.  
    --help               print usage information.  
    --output-tags        Adds XML-like tags to diagnostic messages.  
    --verbose            set verbosity level (’errors’, ’warnings’, ’information’, ’debug’, default is ’warnings’).  
    --version            give version information.  
/usr/local/bin/genesis-g3 --batch --execute "echo ’---\n’" --execute ’list commands’  

The four arguments to the “--verbose” option flag (“errors”, “warnings”, ’‘information”, and “debug”) generate increasing levels of output by the G-Shell. They may be invoked at startup in the following way, for example,

    $ genesis-g3 --verbose warnings

Note that “warnings” defines the default level of output.

Controlling Output from the GENESIS Shell

The verbose Commands

In its default state, with the exception of error messages, the G-Shell generates minimal output. This means that in the default state, if output occurs then something is wrong.

The amount of output generated by the G-Shell is controlled by the set_verbose option. This option recognizes several arguments that generate increasing amounts of output. They include the default setting errors which displays only error state messages, also warnings which displays warning and error messages, information which displays information, warning, and error messages, and the most prolific, debug which is used for software development and also generates maintenance errors. To use the set_verbose option in the G-Shell, enter, e.g.

    genesis > set_verbose debug

To return the shell to its default verbose state, just enter “set_verbose warnings”. To check the state of the verbose flag, enter

    genesis > show_verbose  

The help and list Queries

The G-Shell recognizes a help query. In the absence of an argument, i.e. just entering “help”, an error message is generated that contains the recognized sub-topics, e.g.

    genesis > help  

Similarly, in the absence of an argument the list query generates an error message that contains the recognized argument types:

    genesis > list  

We can then find help on a specific topic, for example, command

    genesis > help command  

To find help on a specific sub-topic the list query can be used to find, for example, the commands available to the G-Shell, e.g.

    genesis > list commands  

We can then obtain help on a specific command with, for example

    genesis > help command output_add