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question about files?

 
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# 8  
Old 12-10-2003
Quote:
Originally posted by Neo
Perfect, something like:

Code:
cat /dev/zero | dd of=test.file bs=20000

Thanks!

Not sure how to make 20MBs from this Smilie Perhaps someone can assist? I tried bs=20000 but it was HUGH!!! Much bigger than 20MB!!!!

Neo
Don't try this at home Smilie .... it just keeps growing bigger and bigger without bounds until it fills up the disk !!

I even tried:


Code:
cat /dev/zero | dd of=test.file bs=1

But GROWS AND GROWS on my Linux box... hmmm?

PS: On Linux we have both /dev/zero and /dev/full ....
# 9  
Old 12-10-2003
Code:
#!/bin/bash

while ["$f_size" -ne "$desired_size"]
do
        cat /dev/zero > tempfile
done


so $f_size would be :
f_size=`filesize name of empty file`

and $desired_size would be:
desired_size=whatever size you want



oh, i guess cat /dev/zero would go on forever as neo had said before.. ok so pick a file thats not to big to cat to your file.
# 10  
Old 12-10-2003
Quote:
Originally posted by norsk hedensk
Code:
#!/bin/bash

while ["$f_size" -ne "$desired_size"]
do
        cat /dev/zero > tempfile
done

.
Thats a great approach by norsk hedensk and will work because it tests the size of the file that is written.

I'm still confused as to why the simple cat |dd pipeline will not work with /dev/zero......Smilie
# 11  
Old 12-10-2003
Well, I'm a pro...so I tried it at home despite your warning...

dd if=/dev/zero bs=1048576 count=20 of=20meg

seems to work fine. Smilie
# 12  
Old 12-10-2003
Quote:
Originally posted by Perderabo
Well, I'm a pro...so I tried it at home despite your warning...

dd if=/dev/zero bs=1048576 count=20 of=20meg

seems to work fine. Smilie
Well, didn't mean you, Perderabo Smilie

This also works, thanks.....

Code:
cat /dev/zero |dd  bs=1048576 count=20 of=20meg_again

....as one might expect.

Neo
# 13  
Old 12-10-2003
Solaris has a mkfile command that does this. I don't know if other OS's have this also.
 
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