Preface text output with Print

Question

In the output of a script that calls Mathematica I would like to be able to differentiate lines printed by mathematica from lines printed by something else. I thought of prefacing lines printed by Mathematica with for example "m:". Is this possible?

Do you mean that you want to change how Print behaves without having to change the code that uses Print? — Szabolcs, Jan 12 '23 at 13:22
Yes. Exactly. I just want to change Print and not change any other part of the code. — Kvothe, Jan 12 '23 at 13:24
Have you tried using the Villegas-Gayley trick to override Print? — Szabolcs, Jan 12 '23 at 13:40

Kvothe · Answer 1 · 2023-01-16T15:43:22.177

1

As suggested by Szabolcs, I used the Villegas-Gayley method

Unprotect[Print];
Print[args___]:=Block[{$inMsg=True},
Print["|m:>",args,"<:m|"]
]/;!TrueQ[$inMsg]
Protect[Print];

This works well. Ideally I could do the same also for warning messages but I haven't quite figured out yet what the appropriate change would be to Message.

edited Jan 16 '23 at 15:43

answered Jan 16 '23 at 15:32

Kvothe

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Just a small comment: you don't need result, just write Print["|m:>", args, "<:m|"];. – Domen Jan 16 '23 at 15:41
Of course you are right. Thanks. – Kvothe Jan 16 '23 at 15:42

Preface text output with Print

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