CLI commands can be divided into two types: basic commands and extended commands.
Basic commands are commands that modify the environment in which other CLI commands are executed. You use basic commands to set parameter values, define command aliases, check command status, or log in and log out of the server. Basic commands always execute in the foreground.
Extended commands are commands that interrogate or modify the topology of managed objects, their properties, and their attributes. You use extended commands to perform several functions:
Locate managed objects in the managed object topology
Enable or disable modules
Acknowledge or delete alarms
By default, extended commands run in the background. You can configure extended commands to run in the foreground.
In session mode, commands execute in either the foreground or the background.
Foreground – Commands that execute in the foreground run to completion. These commands send their output directly to the screen unless otherwise redirected. Only one command at a time can run in the foreground. Basic commands can only run in the foreground. Extended commands run in the background by default, but can be configured to run in the foreground.
Background – Commands that execute in the background run asynchronously and by default send no output or diagnostic messages to the screen. Output is buffered and can be displayed later by explicit request. Unlike the UNIX shells, only one extended command can run in the background at a time. While this command is running in the background, any number of basic commands can run in the foreground. By default, extended commands run in the background, although you can specify that extended commands run in the foreground. Basic commands cannot run in the background.
The CLI also supports aliases. You can define a shorthand term or pseudonym for a more complicated command and its parameters. User-defined aliases persist across different CLI sessions.