Shell Programming and Scripting

I have 2000 files named like "file-fr0000.log", "file-fr1999.log"...
I wanna generate the file names automatically in the following c shell script:

Code:

set fr = 0
while ($fr <= 1999)
    grep "ENERGY" file-fr$fr.log > data.dat
    @ fr = ( $fr + 1 )
end

The above will generate file names like "file-fr5.log" instead of the intended "file-fr0005.log".
How can I generate a series of number with fixed width like "0005", using zeros to fill those vacancies?

Appreciate your time!
Todd

Code:

FILENAME=`printf "file-fr%04d.log" "$N"`

printf should be a builtin in most shells, not sure about csh.

Thanks a lot, it works

Code:

touch file-fr{0,1,2,3,4,5,6,7,8,9}{0,1,2,3,4,5,6,7,8,9}{0,1,2,3,4,5,6,7,8,9}{0,1,2,3,4,5,6,7,8,9}