how to create file with a specific file size
 

I am looking for a tool that can create a file with a specific file size. The content of the file does not matter.

for instance :

[root]#tool-i-am-looking-for filename 567

will create a file called filename with size = 567 bytes.


I know that via touch you can create a file, but it will only create a file with zero bytes length.

does a tool like that exist in linux ?

dd if=/dev/zero of=filename bs=567 count=1

dd if=/dev/zero of=newfile bs=1 count=567

"dd" is the ultimate power tool--use with caution!!

Edit--now you have 2 very different methods!!! (We did NOT rehearse this....;))

Many thanks !

LOL. Not sure, but I think the way I wrote it would be faster.

I expect you are right--although mine took less than 1 second.

I did it that way because I had first attempted to use /dev/random and was getting strange results---It **appeared** that maybe dd did not like off-beat block sizes.

jiml@Dadsbox:jiml> time dd if=/dev/zero of=newfile bs=1 count=567
567+0 records in
567+0 records out
567 bytes (567 B) copied, 0.001906 seconds, 297 kB/s
0.00user 0.00system 0:00.04elapsed 20%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (1major+264minor)pagefaults 0swaps
jiml@Dadsbox:jiml> time dd if=/dev/zero of=newfile bs=567 count=1
1+0 records in
1+0 records out
567 bytes (567 B) copied, 8.4e-05 seconds, 6.8 MB/s
0.00user 0.00system 0:00.00elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+266minor)pagefaults 0swaps


Actually, I had wondered what it would do with the "odd sized block" as well, but it didn't seem to care in this case.

I agree---84 microseconds is a lot faster than 1900 microseconds!!! Doing something like this all day using my method could have cost someone a coffee break......:eek::eek:

All seriousness aside, there's no question that the larger block size is the right answer....