Visit Our UNIX and Linux User Community


File being used/written


 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers File being used/written
# 1  
Old 10-12-2001
Question File being used/written

Hello,
Which command in unix can tell whether a file is being used/written by another process.

e.g. If one process is copying a very big file in some directory and there is another cronjob process which checks for a new file and in this directory and process the file. I want to check, if the file is still being written by the last process.

Sanjay
sanjay92
# 2  
Old 10-12-2001
Code:
#!/bin/ksh

x=`cksum File_Name.exp | awk '{print $1}'`
#sleep 1
y=`cksum File_Name | awk '{print $1}'`
if [  $x = $y ] ; then
  echo "Both are same" $x $y
else
  echo "Both are different" $x $y
fi

This method will work to find out, if the file is still being written by comparing the two snapshots of checksum of file.

Is there any other good method ?

Thanks for taking your time.

Sanjay

added code tags for readability --oombera

Last edited by oombera; 02-18-2004 at 04:11 PM..
sanjay92
# 3  
Old 10-12-2001
If you have lsof you can use that to see
what files are open. You can use...
lsof -F File_Name.exp
...and use that output. I would suggest reading
the man page carefully though. There are alot
of "note" and options.

All said and done though your solution appears
to be simple and if it works...I say stick
with it. Smilie
# 4  
Old 10-13-2001
Thanks for reply.
Unfortunately, I did not find isof utility/command in my unix system. I have SunOS 5.6 Generic_105181-23 sun4u sparc SUNW,Ultra-Enterprise.
Is this utility has to be installed seprately or may be not in my path listing and also I did not find man isof as well.

Sanjay
sanjay92
# 5  
Old 10-13-2001
Yes. It normally isn't installed (until revently).
You'll have to go get it, build it and install
it.

Go to this link...
http://www.cert.org/security-improve...s/i042.05.html

...it's the best reference for me...Smilie
 

Previous Thread | Next Thread
Test Your Knowledge in Computers #68
Difficulty: Easy
Awk is abbreviated from the names of the developers - Aho, Weinberger, and Kernighan.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

To check if a file is open and in use (logs are being written to it)

Hello Experts, I need to write a shell script to check if a file is open and something is being written to it. I want to know how OS handles it. I checked with lsof command but it is not working. For a test I did this. while true; do echo `date` >>abc.txt; done then I checked lsof |... (5 Replies)
Discussion started by: shekhar_4_u
5 Replies

2. Programming

How to prevent a C++ program reading a file that is still being written to.?

Hi, Hopefully someone can help. We have a process that writes a file using Connect Direct to our local Solaris server and then our C++ program will pick up the file and process it. Unfortunately, because of the size of the file, the C++ program is processing the file before it has finished... (7 Replies)
Discussion started by: chris01010
7 Replies

3. Shell Programming and Scripting

Notification as popups when a file being written

I would like to know Is it possible to get a notification as pop-up in linux when a folder with extension '.aqs' written a popup should come as " The folder has been written " Thank you in advance (5 Replies)
Discussion started by: bal_nair
5 Replies

4. UNIX for Advanced & Expert Users

How to copy a binary file while the file is being written to by another process

Hello, Can I copy a binary file while the file is being written to by another process? Another process (program) “P1” creates and opens (for writing) binary file “ABC” on local disk. Process P1 continuously write into ABC file every couple of seconds, adding 512-byte blocks of data. ABC file... (1 Reply)
Discussion started by: mbuki
1 Replies

5. UNIX for Dummies Questions & Answers

12. If an ‘88’ Record with BAI Code ‘902’ was found on input file and not written to Output file, re

This is my input file like this 03,105581,,015,+00000416418,,,901,+00000000148,,,922,+00000000354,,/ 49,+00000000000416920,00002/ 03,5313236,,015,+00231036992,,,045,+00231036992,,,901,+00000048428,,/ 88,100,+0000000000000,0000000,,400,+0000000000000,0000000,/ 88,902,+0000000079077,,/... (0 Replies)
Discussion started by: sgoud
0 Replies

6. Shell Programming and Scripting

Apply Password to already Written XLS File.

I need to apply password protection to a xls file.I had looked at SpreadSheet::WriteExcel but problem being i dont want to write the contents of file again as the formatting the file would be a pain. Is there way in which i write a entire file in one go , something like this ... (0 Replies)
Discussion started by: dinjo_jo
0 Replies

7. UNIX for Dummies Questions & Answers

Appending something to output before being written to a file

Hi, I'm quite stuck with what I thought should've been simple but I just can't seem to do it. Firstly, I have the following done in bourne shell: cat datafile | tr '' '' >> newfile echo "$fullfilepath" >> newfile i want to have the output of that echo put on the same line as the output... (4 Replies)
Discussion started by: Darkst
4 Replies

8. Programming

Unix File has 000 access when written

Good day! I would just like to ask about an issue I encountered. There is a Java program (version1.3) that we use that is hosted in Unix (HP-UX B.11.11 U), and one of its functions copies a file and writes it to another directory. It usually runs fine, but one day, it wrote a file that had 000... (2 Replies)
Discussion started by: mike_s_6
2 Replies

9. Shell Programming and Scripting

Checking a file is not being written to

Hello All I am attempting to write a shell script (bourne shell script) which will copy a tar'd and compressed file from a directory to a staging area but will not know whether the file is still open for write since files are being ftp's to my site at random times during the day. Once I am... (14 Replies)
Discussion started by: kanejm
14 Replies

10. UNIX for Dummies Questions & Answers

Operating on a file being written by another application

Hi, I have a directory that is used to store files generated by another application. Each file is huge and can take some time to produce. I am writing a shell script to check the names and dates of the files and do some functions on the ones that are not being written out. My question is, if I... (3 Replies)
Discussion started by: GMMike
3 Replies

Featured Tech Videos