UNIX for Dummies Questions & Answers

fuser is used to check whether a file is in use by a process or not.

I was putting some information in a file via a background process and was doing a cat to see the contents.
It gave me the pid of background process followed by stop.
Understood only half, stopped because it was writing on it and therefore i won't be able to cat. But what does stop mean and how can i resume it.

Further fuser showed me that process was writing in the file by the suffix "o", but on running it a few times i got the same result.
My background process stopped.
I wanted to check via fuser whether that file is being used in a script and then do some processing from it.

Please help

i believe you have run into a problem wiht opening an active file.

When you cat a file, it is not like tail -f, which allows you to continue viewing updated data in the file. Cat shows you the file at the instant it is viewed with cat. So it would make sense that your copy would "stop" at a certain point. You would have to cat the file again and again and again, over and over to continue viewing the additions to the file.

I think tail -f <filename> would be a better use.

Oops,

You totally misunderstood me, what you are talking about is perfeclty ok.

But when i do a Cat, the background process which was writing to that file stopped. ( I found out this by doing a ps -ef | grep name_of_bak_ground )

It showed stopped, whats this stopped and it never resumed.
I thought to do a fuser, so when the process is not writing then i should Cat the file, but on using fuser the same thing happened.
My backgournd process stopped again. Why?

I can;t do a tail because i need the whole file, so what should i do now.

what is the background process doing with the file you're trying to view? how do you start the background job? please post your command line ...

My background process is writing to that file.
Something like
prstat -n 5 >> file &

This is executed every minute.

i just tried that line on a solaris 8 box and it stayed running in the background even after several "cat file" ... try this and see if it helps ...

Code:

prstat -n 5 < /dev/null  >> file &

btw, the job stayed running the whole time on my test box ... there should be no need to rerun the job every minute ... however, verify for your os platform ...