topic Re: Problems regarding fixed file size on Unix in Operating System - HP-UX

Problems regarding fixed file size on Unix

kamlesh33 — Mon, 21 Mar 2011 13:05:51 GMT

Hi All,

How can i restrict writing the data beyond fixed file size?

i.e. suppose my file is of 1024 bytes. So, i want to restrict writing the data only of 1024 bytes. Beyond 1024 bytes no data to be written on that file. How can I do this?

Re: Problems regarding fixed file size on Unix

Steven Schweda — Mon, 21 Mar 2011 13:18:59 GMT

Disk quotas?

Why do you care? Is there some actual
problem which you are trying to solve?

Discarding your previous thread on this topic
may not be the best way to accumulate useful
information.

Re: Problems regarding fixed file size on Unix

kamlesh33 — Mon, 21 Mar 2011 13:37:33 GMT

as we can use

dd if=/home2/kamlesh/ of=kk.txt count=1024

for creating kk.txt file of 1024 byte.

Now, i want to restrict the data upto 1024 bytes only. How can I do that?

Re: Problems regarding fixed file size on Unix

James R. Ferguson — Mon, 21 Mar 2011 14:11:01 GMT

Hi:

> dd if=/home2/kamlesh/ of=kk.txt count=1024

You need to add a block size; the default is 512. A read of the 'dd(1)' manpages might be beneficial.

Depending upon your objective, you could change the permissions of the file, once created, to disallow writes to it.

Regards!

...JRF...

Re: Problems regarding fixed file size on Unix

Hein van den Heuvel — Tue, 12 Jul 2011 18:34:59 GMT

Steven replied...>>> Discarding your previous thread on this topic
may not be the best way to accumulate useful
information.

Yeah, that was my knee-jerk reaction as well.

So i looked back for the topic and found:

http://h30499.www3.hp.com/t5/System-Administration/Creating-Fixed-size-file-on-unix/m-p/2794533#M80618

This is from 'way-back' and I think that's the topic Steven referred to ann myself and others replied to.

So I think what happened is that 'kamlesh33' at first continued an old conversation. This was noticed by the 'powers that be' and a new topic was forced.

I for one, and others, had not noticed the old topic and we made an effort to help.

Our replies and work appear to be deleted without a warning or bounce-back.
Why not just leave well enough alone, or LOCK the old topic.

I find it extremely disrespectful for my work to be thrown away without cause or recourse.

I don't need that treatment.

I'm pissed! (not at kamlesh33)

Hein.

:-(.

Re: Problems regarding fixed file size on Unix

Dennis Handly — Mon, 21 Mar 2011 15:09:53 GMT

>How can I restrict writing the data beyond fixed file size?

Possibly by setting up the file security so only a specific application (possibly SETUID) can write to the file and it will know about your size limitation.

Re: Problems regarding fixed file size on Unix

TwoProc — Mon, 21 Mar 2011 16:16:59 GMT

About the only thing I can think of that you could create an lvol the size of the file that you want, and use that /dev/vgxxx/lvolxxx as the file name for your program(s).