This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)
Session Customization
Mathematica allows almost every aspect of sessions to be customized, under full programmatic control.
$Pre function to apply before each input is processed
$Post function to apply to each output
SetOptions globally set options for functions, notebooks, and the front end
On, Off switch messages on or off
SetDirectory set the current directory
$Path list of directories to search for files
Low-Level Customization
EvaluationDynamic Updating Enabled switch dynamic content on or off
$Output  ▪ $Urgent  ▪ $Epilog  ▪ $IgnoreEOF  ▪ ...