Question

How to redirect Mathematica printing and error printing to files?

Sometimes, a Mathematica program

• 1) uses Print[] to print messages,
• 2) sometimes, there is side-effect type of printing by some functions without any explicit Print[]
• 3) and sometimes there is error printing.

How to redirect the above three varieties of printing to (separate) text files, so they can be archived (separately) when the Mathematica kernel is closed?

Answer 1

Print[] by default outputs to the stream $Output. Messages go to the $Messages stream. You can redefine these two global variables to redirect the output to a file:

stream = OpenWrite["out.txt", FormatType -> OutputForm]
$Output = {stream}