Re: A new utility: trv

[Giuliano Colla]

I don't claim that trv is a revolution in computer art, deserving that 
my portrait be hung in the hall of fame among Ritchie, Thompson, Stevens 
and Thorvald. It's just handy.

Of course it can be implemented with a bit of shell scripting. Actually 
*it is* implemented as a quite trivial shell script. You just prepend 
#!/bin/sh to your "for x in `find . -type d`.. etc. you save it as 
"trv", make it executable, and you've got "trv". I've implemented 
differently, because I noticed that sometimes "find ." gets confused 
when crossing filesystems, but it's just a matter of personal taste.

But the same holds true for a lot of other utilities: In the RedHat 
install scripts you have "service" which saves you typing 
"/etc/rc.d/init.d/"; "vdir" is nothing but an "ls -l -b". And why 
provide "ls" when "stat * | grep File:" (or a more sophisticated sed 
filtering) provides you the same information? You don't need "vim" when 
you've got "vi". Anything done by vim can be done with vi, with some 
extra typing. You don't need Emacs when you've got vim. It's just a 
matter of extra typing and a bit of scripting. The problem is that if 
you save extra typing and scripting you save time and errors.

The Unix principles, set by those who rightfully deserve a portrait in 
the hall of fame, are to provide small pieces which combined together 
perform powerful actions, to never duplicate efforts, and to provide as 
concise commands as possible, to save typing and typing errors.

That's the value of "trv". A small tool which provides recursion for 
whatever command you may think of, be it an existing utility or a shell 
script. It's concise, doesn't force you to add an -R option to whatever 
script you think, you may concentrate of what you're doing. It's not the 
implementation that matters, it's the concept. Which, btw, isn't mine. 
One more reason not to have my portrait in the hall of fame.

Cheers,

Giuliano

p.s. The versions of find I have around on RHEL (findutils 4.1.7) 
doesn't support the -execdir action. When did it pop up?

Alfred M. Szmidt ha scritto:

>   Once  findutils does the deacent thing...
>
>   cat >> $HOME/.env <<EOF
>   trv() {       
>            find . -type d -execdir "$1" \;
>   }
>   EOF
>
> Don't see why this would be decent, since it can already be done with
> a bit of shell as I already pointed out.  What would happen if you do:
>
> find . -type f -execdir "echo {}" \;
>
> for example?
>
> Cheers!
>
>  


--
Ing. Giuliano Colla
Direttore Tecnico
Copeca srl
Via del Fonditore 3/E
Bologna (Zona Industriale Roveri)

Tel. +39 051 53.46.92 - +39 335 610.43.35
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