Editing File In-Place to put tab before UpperCase Letters

ranjan_jajodia has asked for the wisdom of the Perl Monks concerning the following question:

Hello Monks,
I have a file whose entries are in the following format:

JohnGalt
DagnyTagart
HenryHankRearden
...

I want the content to be in the following format:

John Galt
Dagny Tagart
Henry Hank Rearden
...

i.e, putting tabs(\t) or spaces(\b) before every Upper case letter. Is there a easy way out like doing it by in-place editing. I think s or tr cannot be used here and i need some way to insert character.
Could any one point me in the right direction? If it is not possible than i would have to write a complete script to do that which i feel is not needed here.

Ranjan
--Let Logic Rule--

Comment on Editing File In-Place to put tab before UpperCase Letters

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Re: Editing File In-Place to put tab before UpperCase Letters by Zaxo (Archbishop) on Jul 23, 2005 at 06:19 UTC
Let's do it in unicode, `perl -pi -e's/(\p{IsUpper})/\t$1/g' text.txt` If you have some way of determining whether you want spaces or tabs, you should say what it is. After Compline, Zaxo	[reply] [d/l]
Re^2: Editing File In-Place to put tab before UpperCase Letters by ranjan_jajodia (Monk) on Jul 23, 2005 at 06:32 UTC
Thanks Zaxo for the solution. Sorry for the ambiguity regarding whether I wanted tab or space. Ranjan --Let Logic Rule--	[reply]
Re: Editing File In-Place to put tab before UpperCase Letters by Your Mother (Archbishop) on Jul 23, 2005 at 06:23 UTC
Slight mod to avoid leading space and need for capture. Puts a space (" ") instead of a tab. "\b" is not a space but a boundary. `perl -pi -e 's/(?!\A)(?=\p{IsUpper})/ /g'`	[reply] [d/l]
Re^2: Editing File In-Place to put tab before UpperCase Letters by ikegami (Patriarch) on Jul 23, 2005 at 07:09 UTC
Putting "\b" in the string would add a backspace, not a word boundary.	[reply]
Re^3: Editing File In-Place to put tab before UpperCase Letters by Your Mother (Archbishop) on Jul 23, 2005 at 07:19 UTC
Er, quite right, of course. I was thinking of the left side. Pattern match--boundary, interpolated string--backspace.	[reply]
Re^2: Editing File In-Place to put tab before UpperCase Letters by ranjan_jajodia (Monk) on Jul 23, 2005 at 06:30 UTC
Thanks for the solution and additional information. It works perfectly. Ranjan --Let Logic Rule--	[reply]